Opera browser's VPN is really working?
My impression is, it is not working.
I think you should be asking this on the Opera Forum, not here. Vivaldi has no VPN and no plans for one.
Well, depends on what you define as "working". Like, if it's working as a good thing for Opera, or working as a VPN should, etc, etc.
While anyone can have an opinion on it (and there are some easy to find opinions/articles about Opera's VPN), it's like @Pesala said, the Opera Forums (or other Opera-dedicated websites/communites) are probably a better place for that question.