Bootloader Trap One Plus 7 Pro

I use e on a One plus 7 pro. Unfortunately, I didn’t notice that I shouldn’t go to the last update because it’s faulty. Today I wanted to go back to an old working version. So I installed TWRP in fastboot mode. After a restart, the phone now hangs in the bootloader. Can someone help me?

Wasn’t TWRP already installed ?

I installed the OS (e) via TWRP. In recovery mode, however, only lineage recovery was available. So I installed TWRP again.But I think I made a mistake. I don’t think the device can be saved anymore.

Ich habe über TWRP das OS (e)installiert. Im Recovery Mode war dann allerdings nur noch die Lineage Recovery verfügbar. Also habe ich erneut TWRP installiert.Dabei ist mir wohl ein Fehler passiert. Ich denke das Gerät kann ich abschreiben ;(

Don’t know if it can be applied to your phone but the following howto could help :

Thank you for your tip. I’ll try it out the days and report it.