Ok I wil try it. Thanks!

Ok I like fastboot Idea. Could you tell me more? Is there a guide on how to do it?

Hi, I did some experimenting and now I cannot install UT on my 6t. All installation guides(that I tried) presume that you have >android 9 installed on the device.

Played a little bit with it and now I cannot select "recovery" in fastboot. It just boots the system. Any Thoughts on that?

Yes!! Downgraded as you suggested all my data is here, the phone works. Great job on the installer btw. That thing works like a charm. And now to backing up my data...

Same here, stuck on boot warning screen.
Is there a way to at least recover the data before I go messing around with it?