Hello. I have an issue where, basically what happens is that I drag a tab from one monitor to the other. The tab correctly expands once I release the mouse, but the thumbnail persists. After that, the only solution is to restart the computer. Shutting down the Firefox process tree does nothing; restarting explorer.exe to redraw the Desktop does nothing. That thumbnail is a persistent little bugger, and it overlays itself on top of every other window as well, making it quite bothersome. The curious thing is that this bug is *old*. Like, *old* old. It's actually one of the reasons I originally switched away from Firefox about six or seven years ago, which is why I'm so surprised that it's still around and that nobody is talking about it, according to a quick Google search. Add-ons, cache, or similar things can't be the problem, because this is essentially a reinstall of Firefox. I hope you can figure this one out. As you can imagine, having to restart the computer every once in a while after dragging a tab from one window to a new one is not really realistic long-term.