Wanted to chime in on many of the issues I have come across with Opera GX one of them being that it seems if a user has Opera GX Sync enabled he will be greeted with occasional all data wiping once their browser gets an update. - Yes this has happened to me.

There are quite a few forum posts here that tackle the issue of extensions being removed suddenly, bookmarks disappearing without any backup file. passwords or anything pretty much related to what Opera syncs into the cloud with your user profile.

I have a work computer using Opera GX and home computer, one has sync enabled and one doesn't. You can probably guess which one has had multiple data wiping happening in the past year.

I am almost 80% certain it's the fault of sync and it needs to be addressed. I would highly suggest everyone who doesn't want to make full browser backups every week to just disable opera sync all together. It's more headache than there are benefits.