I'm running on a Dell laptop using an external monitor. I'm using Windows 10 Pro and Firefox 72.0.1.
Every 5 minutes or so, the screen goes crazy. It's blacked out with only the outlines of the cards showing and some text. I can play if I can guess at what is showing. Zooming and unzooming the screen causes some of the cards to appear, but the background and my hand are still blacked out. But when I then make a play, it goes back into full-bad-mode.
Everything works fine on my tablet, it's just the PC version that has video problems.