I just looked into moparts with a fresh (no add ins or extensions) install of vivaldi, no pop ups at all. It's a chrome derivative, you might want to give it a shot.

There's one caveat, I also use https://winhelp2002.mvps.org/hosts2.htm hosts file, whatever pop up you're seeing may be blocked there in my hosts file before it gets to the browser. Since I can't see what you do I've got no way to check my file for it.