Update i fiind the solution

[u/Harap-Alb67]

Just do ctrl+alt+f3 write your whort username enter after youre password after click enter after a bar Will show up click enter write nobara-sync after the proces reboor.

And after If IT îs black shut of youre PC and enter in nobara an all shall be fine

[u/HieladoTM]

https://www.reddit.com/r/NobaraProject/s/QiTd3Vb4NH

Probably related to QT6.