During the updated artifact masters set (or whatever it's being called) an opponent played "plated onslaught" and the image of it remained on the area representing the stack for the remainder of the game. It was usually at the bottom of the stack representation, but did appear above two other effects at some point in the game (which I find particularly bizarre/interesting). There were no gameplay impacting effects.

This was experienced on PC and I am unsure if it's reproducible as that's the first time I've run into the card in the event and don't know if the error is related to the card to begin with.