Thank you so much for this ROM (and LineageOS!) Inkypen!
Just installed the latest yesterday and everything seems fine. I had some troubles after wiping data in TWRP as I also wiped system, cache, aso and thought it would be good to restart in recovery... bad idea, got only to the Fastboot screen, no way to get into TWRP even after reflashing it. Had to use Mi Flash Pro to reflash the original firmware and the go back to the process again to flash your ROM. But I ended up with everything installed.
I also ended up using your unofficial TWRP from here, although I didn't have any problems with the official twrp-3.7.0_9-0:
You can find the latest Mi Flash Tool Pro here in case you need to reflash an original ROM:
xiaomitools.com
And official firmware to flash (I used global):
Download Xiaomi Mi Mix 3 5G Firmware. Model codename is andromeda. You can flash or Update Software your Xiaomi phone from MIUI stock
mifirmware.com
Flash it from the "Mi Flash" tab in the Mi Flash Tool Pro program
- Click on "Select" and browse to the folder where you extracted the official ROM
- Then select "clean all" down right of the Mi Flash window -> flash_all.bat
- Then hit the "flash" botton. It will take a long time to reflash everything and if you get an error, it's probably the drivers for your Xiaomi phone or bad cable, I use a hub as it seems to work better with Xiaomi...
To check if you're ok with the drivers, you should get a device number when you do "fastboot devices" from an adb command window. If you get a warning triangle under Android device (or other) in the device manager, try to update the drivers from there (you have all the drivers needed in the MiFlashPro folder under Program Files x86.