I'm having the same issue, too. And nobody seems to care. I can't even log into my Opera account with my tablet. It doesn't work in Opera, but it does in Chrome or Vivaldi!
I get the impression that it's not worth using niche browsers like Opera, Vivaldi or Brave. They promise better experience by more features or more privacy, but they fail in delivering the basics. In Opera's case it's the syncronization and minor and major other flaws. And I could say the same about the other two.
I'm spending so much time to set things right, often without result. It's annoying, really. In theory, Opera is a beautiful browser with nice features, but it leaves you alone in practice very often. And in cases like this, nobody listens. Unfortunately,!
