@xb70:
The way burnout426 explained it is right on spot. Opera introduced the profile migration problem with version 102.0.4880.16 (the "first" move to version 102). It worked for some and not others through the next few releases. For me it didn't work at first so I rolled back to 101.0.4843.58 (the 101 versions kept the profile in the previous folder) which got all my data back. Opera eventually figured the problem out and posted instructions at https://forums.opera.com/topic/65818/resolving-profile-loss-issues-in-opera-version-102-0-4880-16?lang=en-US&sort=newest_to_oldest . When I went to 102.x.x.33 my profile didn't migrate again so I followed the instructions in that link and it worked. But then during follow-on 102 releases .33 and .40 I assumed my profile information was all moved over to the new locations so upgrading wouldn't hurt anything. But in both of those it didn't find the data and Opera treated me as a new profile, but for some reason when I followed the same instructions to manually migrate it didn't work for those 2 releases.
So for now I rolled back to 101.0.4843.58 again and have all my data. Since then Opera has released builds 102.0.4880.46 and .51, so I keep asking if profile migration has been fixed before I upgrade. I like to keep the latest version of Opera but don't have the time to go through all the headaches of getting my data back. I am a (very) long-time user of Opera, and since my profile bounced back and forth during all the 102 releases, I probably have the "dirty" profile that burnout426 is talking about. Hopefully Opera finds a way to migrate old users and then keep that data in the correct folders moving forward.