Thanks buddy, you nailed it! I use those so I can download and use the Google Dialer from the play store. I deleted the OPO6T dialer instead of just hiding it, so now I don't have a backup dialer.
I've installed OOS 10 from twrp and now it goes always to OOS recovery.
I had Pixen Rom then i had to go to stock.
I've erased data then install OOS 10 in twrp, forgot to install twrp again after install and now it doesn't boot.
I'm without computer now.
Can anyone explain me please the steps to install the zip from twrp? Or the only way its with msmmtool?
I will try it again when i have the PC.
If your OnePlus 6/6t is global/international model: Boot TWRP, flash OOS 10.3.5, flash TWRP installer zip, flash finalize zip, format data, reboot system. Then if you want root: Boot TWRP flash magisk 20.4 or magisk canary ZIP, reboot system.
Just remember formatting data erases everything on your device, pictures, everything...
You could also adb sideload OOS from your computer..
More info on finalize zip, what it is, the link to get it...https://forum.xda-developers.com/oneplus-6t/how-to/guide-rom-flashing-easy-t4143701
I'm not sure exactly what you did or didn't do that made it not boot. You were switching from Pixen rom to OOS 10.3.5?
When I install Pixen: boot twrp, flash OOS 10.3.5, flash Pixen rom, flash finalize zip, format data, reboot system.
Because Pixen has twrp and gapps in the rom zip already so no need to I flash those. If you ever flash a rom and instead of booting system it reboots back to recovery, its probably because you need to format data. In twrp menu format data is under wipe/advanced wipe tab, and then you swipe to confirm the data format. Sometimes people get "wipe data" and "format data" confused. They're not the same thing. I'm guessing that's maybe what happened to you. Not sure I understand.. But if you flashed OOS and then you were in stock recovery afterwards its more than likely because you didn't flash twrp recovery after you flashed OOS and you didn't format data. And then you booted back to your Pixen installation, that's because you only installed OOS on one slot and you still had Pixen on the other slot and didn't wipe..
To get it right just: boot twrp, flash OOS 10.3.5, flash Pixen rom, flash finalize zip, format data, reboot system.