Roku Ultra has graphics issue with Plex



When I am trying to decide what movie to watch from the list provided all of a sudden the graphics starts to break up, then I have to go back to the previous page to try and let it reload. This problem only occurs on 1 out of 4 Roku's I own and the issue occurs on other televisions as well in different rooms using this same Roku. My wife has a Roku 4 hers works fine but when I try my Roku Ultra on her television it happens there to. I would greatly appreciate any expert help with this problem. I myself am quite tech savvy but his one has me befuddled. I look forward to all help. Thanks for the time.