It's really weird. Sadly we have no idea why, we're gonna look out for the cause.
It does seem like it's dependent of one's computer though because this bug didn't seem to be encountered before by any player I got feedback from
Still, really sorry for this inconvenient, I hope you can still play the game by going out of your screen and dragging it back to it? I hope you're enjoying it as well, thanks for playing and reporting this bug!
I wish you a good day/night.