If it were a pure Opera problem, most people would probably have the same problem you mentioned. But it doesn't seem so, otherwise your thread would probably "overflow”.
I don't doubt that you have a problem with Opera, but as I said before, it's probably not just Opera. Unfortunately I can't help you, because I can't reproduce your problem. It is not said that all extensions "work" identically in all browsers. The substructure might not be the same. For example, extensions from the Chrome Web store under Opera sometimes have limited functionality. This is also mentioned by Opera when you load an extension for Opera which is actually intended for Chrome.
By the way: Do you still have this bug with the latest Opera version 72.0.3815.200?