# General[SHARED] [UNOFFICIAL][A12/A13] TWRP 3.7.0 for Redmi Note 11 (spes/spesn)

#### NeoSDAP

##### Senior Member
Well, I found this in a Telegram group (which I know I can't share the link) and when performing all possible tests, it works perfectly with my 4/128 spes.

And as we would all say, I am not responsible for any damage and loss of data caused to your device. I only share the information "as is" and the tests performed by myself on my personal device. Everything is at your own risk.

New Developer on this version:
@jabieff

Previous Developer

@dblenk9 - Telegram

2022/11/06 Update Changelog:
• Synced latest TWRP 12.1 source
• Fixed Android 13 ROM flashing issue (source side)

• Sync with latest TWRP
• Update kernel to MIUI V13.0.4.0.SGCMIXM
• Update blobs to MIUI V13.0.4.0.SGCMIXM
• MTP fixed
• Decrypt works

Features I tried and didn't have any problems
• Flashing and decrypt data from A13 ROMs
• Flashing and decrypt data from A12.1(A12L) ROMs
• Flashing and decrypt data from MIUI-based ROMs (custom and Stock) with A12
• Flashing Magisk
• MTP fully functional

DO NOT USE WITH ANDROID 11 ROMS!!!

Bugs I've found so far
• If you perform a format data, the internal memory will not be recognized in MTP mode of TWRP, which will not be displayed in Windows file explorer
SOLUTION:
Boot into the OS at least once so that the internal memory is rebuilt and made available again in MTP mode

• Sometimes, when checking the option "Automatically reflash TWRP after installing the ROM", it does nothing when it finishes installing the ROM
SOLUTION:
The option seems to be somewhat bugged, so before restarting always reinstall TWRP with the methods that I will explain below

• When flashing some ROMs, "Failed to mount *partition*" errors come out when you finish installing
SOLUTION:
In some ROMs you may get errors when mounting some partitions, commonly "system_ext", "product" and "vendor".

If the installation process ended without any problem and without showing any error code, that's fine, you can restart without problems, This bug has been in all unofficial TWRP for this device

Steps to install

Make sure you have the bootloader unlocked before you start. There are many guides on the internet for that.
Tutorial for Windows only because zero knowledge for Mac and Linux

From PC:

1. Download the latest platform-tools from the Android developer site and extract the zip in an easily accessible folder

2. Download the TWRP image file from here, or from the post attachments
SHA256: 8F25AC88628E6D7BC5E29D8572CF4ACA3499B7D626685654B3C4548323B8D591

3. Restart your device to fastboot mode
Method 1:
Using this adb command if you have USB debugging active on your device
Code:
adb reboot bootloader

Method 2:
-
- After it has completely turned off, press and hold Vol - and the Power button at the same time until the word "FASTBOOT" with orange letters comes out

Method 3:
- Turn off yout device
- Press and hold Vol - button
- Connect the USB cable (previously connected to the PC) to the device and press and hold the button until the word "FASTBOOT" with orange letters comes out

4. Connect your device to the PC

5. Open a cmd window in the folder where you extracted the binaries from the zip from step 1
Easy method: Open the folder, and without leaving it, type "cmd" in the address bar of the file explorer and press enter. Command promt will open a window directly in the folder location

6. Verify that your device is recognized by fastboot using this command
Code:
fastboot devices
If your device has been detected (a serial number followed by the word fastboot), you can continue. Otherwise, check if the drivers are installed correctly, although if you used Mi Unlock and were able to unlock the device correctly on the PC you are using, you should not have problems with that.

- Because this device uses A/B partitions, there is no recovery partition as such, but it is integrated into the "boot" partition. So, first we must boot using the TWRP image.

7. Type this command in the cmd window, but don't press Enter yet, just type it and leave a space at the end
Code:
fastboot boot_
Don't write the "_". This only indicates the space you should leave at the end.
This is how it should look when you write it:

fastboot boot

8. Now, drag the image file (twrp-3.7.0.img) to the command window and drop it above the window. This will make you copy your exact location for convenience.

- The result should be this:

9. Code:
fastboot boot "C:\location\to\your\file\twrp-3.7.0.img"

Quotation marks are only added if the entire location has spaces.
Otherwise, it is displayed without quotation marks.

10. Press Enter and wait a few seconds. The MI logo will come out, and then the TWRP logo.

DONE! You've started perfectly in TWRP

From the device
NOTE: Only use these steps if you want to have TWRP installed semi-permanently

I said "semi-permanent" because when flashing any ROM, and knowing that the "recovery" is integrated into the "boot" partition, it will be lost after leaving TWRP, so you can follow these steps if you want to avoid loss of TWRP.

If you have easy access to a PC, you can be fine with the boot method. If you don't have easy access to a PC, you can follow these steps.

Method 1

2. Now tap on the option "Flash current TWRP"

3. "Swipe to confirm" and the TWRP installation process will begin
Method 2

2. Copy the TWRP image file to the internal memory or SD card from the PC. MTP mode is enabled by default
You can use a USB OTG too

3. Now tap on the option "Install recovery ramdisk"

4. Now locate the file and tap on it.
You can use the "Select storage" button to switch between different storages

5. "Swipe to confirm" and the TWRP installation process will begin
Method 3
1. While in the TWRP menu, tap the Install button

2. Copy the TWRP image file to the internal memory or SD card from the PC. MTP mode is enabled by default.
You can use a USB OTG too

3. Tap on the option "Install image"

4. Now locate the file and tap on it.
You can use the "Select storage" button to switch between different storage

5. In the new menu, select "Install recovery ramdisk" and then "Swipe to confirm Flash"
Remember that with the three methods mentioned above you will lose root access (Magisk), so do not forget to flash it again. These steps are also valid to update TWRP if you already had it previously installed.

Conclusion
I did everything I could but I couldn't find the source code for this TWRP, so I'm sorry for that.

#### Attachments

• twrp-3.7.0.img
96 MB · Views: 1,996
Last edited:

#### NeoSDAP

##### Senior Member
11/11/2022
POST:
- Reverted to previous version as @jabieff TWRP is unable to flash MIUI ROMs due to dynamic partitioning error.

07/11/2022
POST
- Updated to latest TWRP and new developer

19-10-2022
POST:
- Fixed typo and A11 ROMs info added

Last edited:
aing666 and Walden0

#### essor-13

##### Senior Member
Hello and thanks for this tutorial. I tried it on my new red minote 11 and unlike on 3.6.1 TWRP my pin code can't unlock encryption.
It returns :
Code:
Failed to decrypt user 0
Is there a way to solve yhis issue ?

Rom version : MUI global 13013 Stable RGKEUXM
Android version: 11 RKQ1.211001.001

Thanks !

Last edited:

#### jtrakx

##### Member
Hello and thanks for this tutorial. I tried it on my new red minote 11 and unlike on 3.6.1 TWRP my pin code can't unlock encryption.
It returns :
Code:
Failed to decrypt user 0
Is there a way to solve yhis issue ?

Rom version : MUI global 13013 Stable RGKEUXM
Android version: 11 RKQ1.211001.001

Thanks !
I think this version of TWRP works only with MIUI13 A12. You're on A11 version of MIUI13.

essor-13

#### NeoSDAP

##### Senior Member
Hello and thanks for this tutorial. I tried it on my new red minote 11 and unlike on 3.6.1 TWRP my pin code can't unlock encryption.
It returns :
Code:
Failed to decrypt user 0
Is there a way to solve yhis issue ?

Rom version : MUI global 13013 Stable RGKEUXM
Android version: 11 RKQ1.211001.001

Thanks !
This recovery is not compatible with Android 11 ROMs. If you need one for A11 specifically, use version 3.6.1

#### essor-13

##### Senior Member
This recovery is not compatible with Android 11 ROMs. If you need one for A11 specifically, use version 3.6.1
Thanks for the answer. I'm a bit confused about this (I'm really not an expert, far from that). My previous phone was a antic galaxy S7 that passed awaysome days ago. With that phone (at the end I was on LOS 19 I think) there was no encryption issue, I installed the TWRP on a Oreo android version ans I never had android version compatibility issues (let say that is TWRP version x was compatible with android version y is was also compatible with android version y-1). It seems to be different with my new redmi note 11.

I also had a backup / restore issue (TWRP 3.6.1) : I did enter the TWRP by unlocking with my pin code, did the backup (data, system and also data+system in case of) and I wanted to restore the data backup (I tried to debloat the ROM via adb but I made some mistakes so I decided to restore the backup data + system) and the TWRP showed a warning : "pin must be desactivated before restoring". I tried to ignore the message (I made enough mistakes to be enable to reach the phone's login), the restore operation failed with an "error 255". So I reconfigured the phone, desactivated the login pin, went to TWRP, made the restore (no pin warning) but hen the phone didn't boot correctly (hanged 15 min on the MI startup logo with the three dots on the bottom, but nothing else happens).

I obviously did the backup / restore operation the wrong way. On my S7 it was very easy : I make a full backup, data+system, then I restore it when needed, and no issue at all). So What is the correct way to backup / restore a full system + data with TWRP without having to do a factory reset and then try to restore Titanium backup (which cannot restore correctly all the apps, some need to be resintalled). This solution works, but it is much longer and annoying than restoring a TWRP/nandroid backup.

Thanks !

#### gentano

##### Senior Member
@NeoSDAP You could add sth like 'only for A12/A13'-roms to the title and add a highlighted note, that You need 3.6.1 for A11 roms to the OP.

#### NeoSDAP

##### Senior Member
Thanks for the answer. I'm a bit confused about this (I'm really not an expert, far from that). My previous phone was a antic galaxy S7 that passed awaysome days ago. With that phone (at the end I was on LOS 19 I think) there was no encryption issue, I installed the TWRP on a Oreo android version ans I never had android version compatibility issues (let say that is TWRP version x was compatible with android version y is was also compatible with android version y-1). It seems to be different with my new redmi note 11.

I also had a backup / restore issue (TWRP 3.6.1) : I did enter the TWRP by unlocking with my pin code, did the backup (data, system and also data+system in case of) and I wanted to restore the data backup (I tried to debloat the ROM via adb but I made some mistakes so I decided to restore the backup data + system) and the TWRP showed a warning : "pin must be desactivated before restoring". I tried to ignore the message (I made enough mistakes to be enable to reach the phone's login), the restore operation failed with an "error 255". So I reconfigured the phone, desactivated the login pin, went to TWRP, made the restore (no pin warning) but hen the phone didn't boot correctly (hanged 15 min on the MI startup logo with the three dots on the bottom, but nothing else happens).

I obviously did the backup / restore operation the wrong way. On my S7 it was very easy : I make a full backup, data+system, then I restore it when needed, and no issue at all). So What is the correct way to backup / restore a full system + data with TWRP without having to do a factory reset and then try to restore Titanium backup (which cannot restore correctly all the apps, some need to be resintalled). This solution works, but it is much longer and annoying than restoring a TWRP/nandroid backup.

Thanks !
Because this device uses a different partition scheme (A/B partitions and, apparently, dynamic partitions) it is not necessary to make nandroid backups, since the partitions change size depending on the ROM you install.

If you want to keep everything in order:
- Keep a copy of TWRP and the zip of the ROM you are using to avoid problems in the future.
- If you want a backup of the info on your phone, I recommend you install Magisk and use Swift Backup. It's in the Play Store.

aing666

#### NeoSDAP

##### Senior Member
@NeoSDAP You could add sth like 'only for A12/A13'-roms to the title and add a highlighted note, that You need 3.6.1 for A11 roms to the OP.
Thanks for the correction. I have already modified the title

#### sarib

##### Senior Member
Thanks for the correction. I have already modified the title
Can you please tell me if it's possible to flash twrp via magisk app for root access and for installing twrp itself, actually I've updated my rn11 and insalled October security patch but my custom recovery along with root is overwritten

#### NeoSDAP

##### Senior Member
Can you please tell me if it's possible to flash twrp via magisk app for root access and for installing twrp itself, actually I've updated my rn11 and insalled October security patch but my custom recovery along with root is overwritten
Nope. You need a PC to install the recovery. Something that can also work is to use a phone rooted with Magisk and the ADB and fastboot module

aing666

#### essor-13

##### Senior Member
Because this device uses a different partition scheme (A/B partitions and, apparently, dynamic partitions) it is not necessary to make nandroid backups, since the partitions change size depending on the ROM you install.

If you want to keep everything in order:
- Keep a copy of TWRP and the zip of the ROM you are using to avoid problems in the future.
- If you want a backup of the info on your phone, I recommend you install Magisk and use Swift Backup. It's in the Play Store.
Thanks a lot for those infos. I understand a bit better now.

By any chance do you know a rom (debloated) that works flawlessly (camera, wifi, NFC, BT, etc) with the redmi note 11 ? I had LOS on my S7, that was fine because it made the device last longer, but it wasn't withoutt issues.

#### Appl1

##### New member
am I doing something wrong
Thank.

Last edited:

#### SubwayChamp

##### Senior Member
War mache ich falsch? Hat jemand eine Idee?
Thank.

View attachment 5779933
According to the rules, English is required.

Boot to a different version from TWRP. The v3.62 will help, then flash the v3.7.0 through TWRP. It happens, probably, because some custom recoveries, doesn't allow this version to boot to.

#### Appl1

##### New member
Gemäß den Regeln ist Englisch erforderlich.

Booten Sie mit einer anderen Version von TWRP. Die v3.62 wird helfen, dann die v3.7.0 über TWRP flashen. Es passiert wahrscheinlich, weil einige benutzerdefinierte Wiederherstellungen es dieser Version nicht erlauben, zu booten.
danke werde ich im laufe des tages ausprobieren. Ich habe auf Englisch geschrieben. Verzeihung

#### Oswald Boelcke

##### Senior Moderator / Moderator Committee
Staff member
danke werde ich im laufe des tages ausprobieren. Ich habe auf Englisch geschrieben. Verzeihung
Thanks for the edit of your first post and the switch to English. However, if you check you post above it's again only in German. Did you check your browser's settings if it automatically translates to German even if you wrote in English?

Regards
Oswald Boelcke
Senior Moderator

SubwayChamp

#### Flammable98

##### New member
Can you please tell me if it's possible to flash twrp via magisk app for root access and for installing twrp itself, actually I've updated my rn11 and insalled October security patch but my custom recovery along with root is overwritten
Same ****.. I bought my phone in July... then rooted it... then all these useless security patches for me used to unroot my phone - remove TWRP and the root while have magick app installed. One time tried to reroot and ****ed up so had to reflash again the stock rom (I was with the stock rom before) just lost some data (not a big deal... all apps with their non cloud savable data, settings and etc LOL)
So I am still wondering how to avoid this and properly update without losing the root.
Also when Xiaomi will stop releasing **** small updates every month?

#### SubwayChamp

##### Senior Member
Same ****.. I bought my phone in July... then rooted it... then all these useless security patches for me used to unroot my phone - remove TWRP and the root while have magick app installed. One time tried to reroot and ****ed up so had to reflash again the stock rom (I was with the stock rom before) just lost some data (not a big deal... all apps with their non cloud savable data, settings and etc LOL)
So I am still wondering how to avoid this and properly update without losing the root.
Also when Xiaomi will stop releasing **** small updates every month?
There´s not such a thing; "...properly update without losing the root", any major update causes the loss of root, because of boot partition, but, if the update is only about security policies, then you shouldn´t lost root. Rooting this device can always be done, flashing the Magisk zip over the ROM.

Anyway, you can choose, not to update automatically, so, this is up to you, get it or not.

#### sarib

##### Senior Member
Same ****.. I bought my phone in July... then rooted it... then all these useless security patches for me used to unroot my phone - remove TWRP and the root while have magick app installed. One time tried to reroot and ****ed up so had to reflash again the stock rom (I was with the stock rom before) just lost some data (not a big deal... all apps with their non cloud savable data, settings and etc LOL)
So I am still wondering how to avoid this and properly update without losing the root.
Also when Xiaomi will stop releasing **** small updates every month?
There's a new update "November patch" and I'm now thinking what I should do

### Top Liked Posts

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• 1
Does anyone understand the purpose of this A and B partition scheme? TWRP lets me click either A or B and reboot "to" that partition, and the ROM install will choose one or the other for the install, whichever it says is inactive... it doesn't just always stay on A or B... so I am wondering if we can "use" this new feature in some way to our benefit?
I think this article targets the major goal of this https://source.android.com/docs/core/ota/ab, it seems to me that the main purpose is to provide a way to have updates, not OTG as they claim but safest updates AKA without brick the device, so if the update fails, and device can't boot to the updated slot, at least can boot to the untouched slot (stock updates only flash on the inactive slot) but, in the practice, not always work as intended.
I don't know of this or that specific ROM, but, actually custom ROMs flash all the images/files on both slots, so you should choose, plainly, to reboot to system despite A or B slot, I guess data and cache are shared.
Losing the recovery partition is a PITA.

Also curious if there is any functional difference between the 3 TWRP re-flash methods. ("Flash current TWRP", "install recovery ramdisk", and "always reflash TWRP after ROM install", since the first 2 methods require re-booting to TWRP again from fastboot)
These 3 options are the same, and don't require booting to fastboot nor reboot device to recovery, in order to do so, only in some ROMs is required to reboot to TWRP, after of flash it in the ramdisk partition, when formatting data is required.
• 6
Well, I found this in a Telegram group (which I know I can't share the link) and when performing all possible tests, it works perfectly with my 4/128 spes.

And as we would all say, I am not responsible for any damage and loss of data caused to your device. I only share the information "as is" and the tests performed by myself on my personal device. Everything is at your own risk.

New Developer on this version:
@jabieff

Previous Developer

@dblenk9 - Telegram

2022/11/06 Update Changelog:
• Synced latest TWRP 12.1 source
• Fixed Android 13 ROM flashing issue (source side)

• Sync with latest TWRP
• Update kernel to MIUI V13.0.4.0.SGCMIXM
• Update blobs to MIUI V13.0.4.0.SGCMIXM
• MTP fixed
• Decrypt works

Features I tried and didn't have any problems
• Flashing and decrypt data from A13 ROMs
• Flashing and decrypt data from A12.1(A12L) ROMs
• Flashing and decrypt data from MIUI-based ROMs (custom and Stock) with A12
• Flashing Magisk
• MTP fully functional

DO NOT USE WITH ANDROID 11 ROMS!!!

Bugs I've found so far
• If you perform a format data, the internal memory will not be recognized in MTP mode of TWRP, which will not be displayed in Windows file explorer
SOLUTION:
Boot into the OS at least once so that the internal memory is rebuilt and made available again in MTP mode

• Sometimes, when checking the option "Automatically reflash TWRP after installing the ROM", it does nothing when it finishes installing the ROM
SOLUTION:
The option seems to be somewhat bugged, so before restarting always reinstall TWRP with the methods that I will explain below

• When flashing some ROMs, "Failed to mount *partition*" errors come out when you finish installing
SOLUTION:
In some ROMs you may get errors when mounting some partitions, commonly "system_ext", "product" and "vendor".

If the installation process ended without any problem and without showing any error code, that's fine, you can restart without problems, This bug has been in all unofficial TWRP for this device

Steps to install

Make sure you have the bootloader unlocked before you start. There are many guides on the internet for that.
Tutorial for Windows only because zero knowledge for Mac and Linux

From PC:

1. Download the latest platform-tools from the Android developer site and extract the zip in an easily accessible folder

2. Download the TWRP image file from here, or from the post attachments
SHA256: 8F25AC88628E6D7BC5E29D8572CF4ACA3499B7D626685654B3C4548323B8D591

3. Restart your device to fastboot mode
Method 1:
Using this adb command if you have USB debugging active on your device
Code:
adb reboot bootloader

Method 2:
-
- After it has completely turned off, press and hold Vol - and the Power button at the same time until the word "FASTBOOT" with orange letters comes out

Method 3:
- Turn off yout device
- Press and hold Vol - button
- Connect the USB cable (previously connected to the PC) to the device and press and hold the button until the word "FASTBOOT" with orange letters comes out

4. Connect your device to the PC

5. Open a cmd window in the folder where you extracted the binaries from the zip from step 1
Easy method: Open the folder, and without leaving it, type "cmd" in the address bar of the file explorer and press enter. Command promt will open a window directly in the folder location

6. Verify that your device is recognized by fastboot using this command
Code:
fastboot devices
If your device has been detected (a serial number followed by the word fastboot), you can continue. Otherwise, check if the drivers are installed correctly, although if you used Mi Unlock and were able to unlock the device correctly on the PC you are using, you should not have problems with that.

- Because this device uses A/B partitions, there is no recovery partition as such, but it is integrated into the "boot" partition. So, first we must boot using the TWRP image.

7. Type this command in the cmd window, but don't press Enter yet, just type it and leave a space at the end
Code:
fastboot boot_
Don't write the "_". This only indicates the space you should leave at the end.
This is how it should look when you write it:

fastboot boot

8. Now, drag the image file (twrp-3.7.0.img) to the command window and drop it above the window. This will make you copy your exact location for convenience.

- The result should be this:

9. Code:
fastboot boot "C:\location\to\your\file\twrp-3.7.0.img"

Quotation marks are only added if the entire location has spaces.
Otherwise, it is displayed without quotation marks.

10. Press Enter and wait a few seconds. The MI logo will come out, and then the TWRP logo.

DONE! You've started perfectly in TWRP

From the device
NOTE: Only use these steps if you want to have TWRP installed semi-permanently

I said "semi-permanent" because when flashing any ROM, and knowing that the "recovery" is integrated into the "boot" partition, it will be lost after leaving TWRP, so you can follow these steps if you want to avoid loss of TWRP.

If you have easy access to a PC, you can be fine with the boot method. If you don't have easy access to a PC, you can follow these steps.

Method 1

2. Now tap on the option "Flash current TWRP"

3. "Swipe to confirm" and the TWRP installation process will begin
Method 2

2. Copy the TWRP image file to the internal memory or SD card from the PC. MTP mode is enabled by default
You can use a USB OTG too

3. Now tap on the option "Install recovery ramdisk"

4. Now locate the file and tap on it.
You can use the "Select storage" button to switch between different storages

5. "Swipe to confirm" and the TWRP installation process will begin
Method 3
1. While in the TWRP menu, tap the Install button

2. Copy the TWRP image file to the internal memory or SD card from the PC. MTP mode is enabled by default.
You can use a USB OTG too

3. Tap on the option "Install image"

4. Now locate the file and tap on it.
You can use the "Select storage" button to switch between different storage

5. In the new menu, select "Install recovery ramdisk" and then "Swipe to confirm Flash"
Remember that with the three methods mentioned above you will lose root access (Magisk), so do not forget to flash it again. These steps are also valid to update TWRP if you already had it previously installed.

Conclusion
I did everything I could but I couldn't find the source code for this TWRP, so I'm sorry for that.
2
11/11/2022
POST:
- Reverted to previous version as @jabieff TWRP is unable to flash MIUI ROMs due to dynamic partitioning error.

07/11/2022
POST
- Updated to latest TWRP and new developer

19-10-2022
POST:
- Fixed typo and A11 ROMs info added
2
Hello and thanks for this tutorial. I tried it on my new red minote 11 and unlike on 3.6.1 TWRP my pin code can't unlock encryption.
It returns :
Code:
Failed to decrypt user 0
Is there a way to solve yhis issue ?

Rom version : MUI global 13013 Stable RGKEUXM
Android version: 11 RKQ1.211001.001

Thanks !
This recovery is not compatible with Android 11 ROMs. If you need one for A11 specifically, use version 3.6.1
1
Hello and thanks for this tutorial. I tried it on my new red minote 11 and unlike on 3.6.1 TWRP my pin code can't unlock encryption.
It returns :
Code:
Failed to decrypt user 0
Is there a way to solve yhis issue ?

Rom version : MUI global 13013 Stable RGKEUXM
Android version: 11 RKQ1.211001.001

Thanks !
I think this version of TWRP works only with MIUI13 A12. You're on A11 version of MIUI13.
1
Thanks for the answer. I'm a bit confused about this (I'm really not an expert, far from that). My previous phone was a antic galaxy S7 that passed awaysome days ago. With that phone (at the end I was on LOS 19 I think) there was no encryption issue, I installed the TWRP on a Oreo android version ans I never had android version compatibility issues (let say that is TWRP version x was compatible with android version y is was also compatible with android version y-1). It seems to be different with my new redmi note 11.

I also had a backup / restore issue (TWRP 3.6.1) : I did enter the TWRP by unlocking with my pin code, did the backup (data, system and also data+system in case of) and I wanted to restore the data backup (I tried to debloat the ROM via adb but I made some mistakes so I decided to restore the backup data + system) and the TWRP showed a warning : "pin must be desactivated before restoring". I tried to ignore the message (I made enough mistakes to be enable to reach the phone's login), the restore operation failed with an "error 255". So I reconfigured the phone, desactivated the login pin, went to TWRP, made the restore (no pin warning) but hen the phone didn't boot correctly (hanged 15 min on the MI startup logo with the three dots on the bottom, but nothing else happens).

I obviously did the backup / restore operation the wrong way. On my S7 it was very easy : I make a full backup, data+system, then I restore it when needed, and no issue at all). So What is the correct way to backup / restore a full system + data with TWRP without having to do a factory reset and then try to restore Titanium backup (which cannot restore correctly all the apps, some need to be resintalled). This solution works, but it is much longer and annoying than restoring a TWRP/nandroid backup.

Thanks !
Because this device uses a different partition scheme (A/B partitions and, apparently, dynamic partitions) it is not necessary to make nandroid backups, since the partitions change size depending on the ROM you install.

If you want to keep everything in order:
- Keep a copy of TWRP and the zip of the ROM you are using to avoid problems in the future.
- If you want a backup of the info on your phone, I recommend you install Magisk and use Swift Backup. It's in the Play Store.