Thanks, that helps a lot! So it’s every card on the battlefield, even basic lands, starting after some “exile face down, you may play it” effect. I tried that exact situation (Gonti, and an opponent stealing my cards) and couldn’t trigger it yet, so I need to see what happens in your game:
Go to Settings → Detailed game log and turn it on.
Play until it happens again, and click a land a couple of times.
Click “Open the folder” in that same setting and send me detailed-game.log (and neo.log from the same folder if it’s there).
Those files record every click and what the game did with it, so I’ll see exactly where it gets stuck. Thanks for your patience!