Given how long-standing of an issue this has been, I can really appreciate that this has been hard for you guys to track down! It isn't obvious to me that there's this "one thing" that I do that results in this behavior, so I'm not surprised it hasn't been found/fixed yet. :) I'm not sure if other tool windows are affected. Since I now have a 4k monitor, I started pinning the docked tests window to the side. And when I log in remotely to my laptop with a screen that's only FHD in size, the window is LARGE, but that's because it was previously sized on 4k. All that to say, that seems to be functioning correctly! As far as I've noticed, it the risk/progress bar that seems to float around.
I'll try to keep an eye on it, and if I see some pattern, I'll try to report back. But honestly, to date, I haven't noticed a pattern. Good luck with hunting this one down. Like I said, annoying? Yes. Deal breaker: by all means no. If it was easy to fix, it'd be fixed. So I appreciate you guys keeping a lookout for this. And thanks for a great product!