Good luck with the mobile release!
From what I've seen, when I press the restart button on it's right side it doesn't seem to respond, but clicking on the left side, next to the restart arrow seem to work fine. So maybe it's just a collider thing.
Thanks for coming back and testing for us! Sadly neither of us can reproduce the issue, even if we do weird things like zooming in and out on the page. Maybe it's an issue with some overlay on your screen? I have no idea. We'll keep it in mind though and try to investigate as soon as the error seems to occur for others as well.