- So, even with the original ROM (guess that’s Miui10/Android9?) Poco is not working and just entering Fastboot?
- With all your attempts, did you always get the same behaviours with your Poco (straight to Fastboot)?
- What’s your TWRP version? Make sure that you have the latest (3.3.0)
One thing that could be the issue in your case: You used MIUI-EU ROM, right?.You actually need the stock ROM afaik (no matter if developer ROM or Standard MIUI ROM, but stock).
What I’d do in your case:
- Reinstall MIUI (Android 8.1 stock) using the MI-Flash Tool. This needs to be done from a PC. Make sure that you do not re-lock the device (settings are in the bottom right corner of your PC screen. For flashing you need to unzip the ROM. Explanations are here (the ROMs in the article are not the correct ones, they are Android 9, but the installation instructions are well straight forward).
Then:
- Reinstall latest TWRP via Fastboot.
- Wipe, Data, Dalvik, Cache, System
(you should not have a vendor partition, right?) - Change file system on Data to exFAT and then again to EXT4 (as described above)
- Install /e/ then.