@leocg As I said in my first post: Everything disabled except "Ad blocking", "Force enable zoom" and "Block pop-ups".
This also happens when there are no active (=open) tabs. When I open Opera and go back to screen as in screenshot above the notifications are gone. Some seemingly random time later they are back again and always very close to the number 10. Not first 1 and then some time later 2 etc. No, it starts with 10.