About 24 hours after I posted the problem, it had solved it self. I had mobile version back, and have not dared to switch to desktop mode in fear of being stuck with that But I also think that the setting you choose should stay, and not automatically turn to the other option.

Yesterday my Opera Android app suddenly started showing all web pages in their desktop mode, not mobile mode.

The Opera version is 75.2.3978.72468. Phone is Motorola edge with Android 11.

The settings for "default user agent" is set to mobile but desktop is what is being displayed. I have tried to change it back and forth between the settings, tried to turn off ad blocker, data savings and tracker blocking, force stop Opera, turned the phone off, but it still only shows desktop mode.

Anybody have any idea on how to fix this?