I have proton pass and bitdefender password manager and it doesn't work well on opera for Android (version 91). Sometimes it works. I change Samsung keyboard to SwiftKey and Gboard. Seems to have better results with Gboard.

However I tried opera mini and it works great.

I also tried opera gx for android and same problem as opera standard, and it lacks favorites sync

For now I use opera mini but some functions of opera standard are lacking...

This is annnoying, Opera user from years (presto engine) I dont want tu use another browser but i am considering switching to another if i dont find a solution.