[P8 Lite (2017) Discussion] baffo92:
It's fine, it was only strange to see the rollback of patches, nothing to worry about :)

Everything seems to work fine (FM App runs and I can hear Italian/FM Stations as usual, two IMEIs recognised and I can adjust settings for both SIMs like it was at the beginning).

The only strange thing I have is related to 'Themes' app, which is totally empty (no themes are offered or presented and I surely don't know why, but it's not a problem at all).

I want to share with you what I did if it can be useful to other people, so... here is a personal guide:

RETURN FULLY STOCK FROM a MODDED or a SOFT-BRICKED PRA-LX1 (Tested with an Unbranded Dual SIM Variant bought in Italy, so it's not guaranteed that this will work with Single SIM variant)

Before you read you must know that no one here on XDA will be responsible for any damage that may occour by following this guide, so feel free to ignore it if you are unsure :)

1. My phone was OEM Unlocked (FRP Unlock in Fastboot) and Bootloader was Unlocked (Phone Unlock in Fastboot) and with Stock Firmware (with problems on some apps and stability because I was trying to restore it for two days!)

2. Flashed TWRP taken from this thread

3. Copied the TWRP Backup (you can access internal memory while you are in TWRP recovery) in this path (case sensitive): TWRP\BACKUPS\xxxxxxxxxxxxxxxx\2017-10-18--12-03-00_NRD90M_test-keys (you must change the 'xxxxxxxxxxxxxxxxxxx' with the code you can see on your PC by launching 'adb devices' command.

4. While on TWRP Wipe Data, System, Cache and Dalvik / ART Cache (DON'T CHOOSE ANYTHING ELSE OR YOU WILL COMPROMISE THE PHONE!)

5. Restore the Backup provided by [MENTION=7295200]ChinHon[/MENTION]

6. Now flash the original recoveries (for me 'fastboot flash recovery recovery.img' and 'fastboot flash recovery2 recovery2.img' worked without any problems)

7. Boot the Phone

8. No Setup will be provided, because the Backup is a fully functional image.

9. Now that the phone is working download the UPDATE.APP provided by our XDA friend [MENTION=7295200]ChinHon[/MENTION] and follow his instructions (you can find them some posts above)

10. Assuming you followed [MENTION=7295200]ChinHon[/MENTION] instructions, your phone should be updating from SD (tested with Samsung 64GB SD with exFAT partition: the SD was NOT clean and full of files, but no problems appeared)

11. At the end you will boot on your phone like it was before, but EMUI is 5.0 and patch are from August.

12. Now go to Settings -> Phone Informations (where you see EMUI version, your IMEI, Google patches version, etc...) and 'Become a Developer' by clicking the Serial Number a lot of time.

13. Go to 'Developer Options' and disable Constructor Block (FRP will be Locked)

14. Reboot into bootloader and Relock the Bootloader

15. A factory reset should be prompted, do it!

16 - OPTIONAL. Verify that everything is OK in bootloader (two green text should be displayed)

17. The phone will boot and it is fully stock: the setup will be prompted and you have to insert you informations (like Google Account, Wi-Fi password, etc...)

18 OPTIONAL. If you want to be 100% sure relaunch the update... I did it just to be sure that everything was OK after re-locking bootloader, and I also wiped Data from stock recovery.

19. Everything should be unrooted with Locked FRP , Locked Bootloader and with stock apps fully working (first thing to try are FM Radio App and Camera App).

This guide is not perfect and many steps were repeated just to be sure everything was working correctly...

Only one problem found in my case: no themes are available even if you grant access to the app.

I suppose that if a new version will be released (like Oreo) security checks should pass and the update should work... but we can't be sure.

After messing up with recoveries and damaging everything this is the most stock experience I could achieve.

Obviously a big thanks goes to [MENTION=7295200]ChinHon[/MENTION] who provided roms, recoveries and even a great support to me (Thanks man, really appreciated!).

So, what are you waiting? Go and give him a lot of thanks in his topic!