if changing the browser fixes it, it’s likely an update in your browser.
I’m using firefox and opera GX (that one mostly for streaming services)
a couple of weeks ago, opera GX started misbehaving, and videos became choppy. a few days later, an update came and fixed it.
it wasn’t the fault of any of the video services I was checking, they did something to the material acceleration.
Sketchup web hasn’t pushed an update recently, so they didn’t change anything (as far as I know).
therefore my best guess is that your browser updated and changed something.
you should give that feedback to Brave’s devs, if they don’t know it’s bugging, then there is no bug to fix. and they can check what got updated in the last weeks that can cause this.