I did read up on Opera before deciding to try it, and I know about it being owned by the Chinese. I don't intend to do anything sensitive when using it, like banking or purchases. I just needed something that would let me get around this place and other XenForo sites.I dunno, Firefox has been working fine for me on cfc across my four PCs. Have you tried disabling any/all add-ons?
IE has been deprecated for some years other than security updates anyway.
I specifically recommend against Opera, it got bought out by China. Any of Chrome/Vivaldi/Opera are going to render the web comparably, they all use the same engine.
Hopefully the next version of Firefox will be less... troublesome.
As far as I'm concerned, this is a trial run, to see how it works. If something goes wrong or if I find it can't do something I want it to do, I'll try Chrome... although I did try Chrome a couple of years ago and didn't like it.