As the description says, when the option, "Show current key in tooltip" is enabled, a section is added to the bottom of every tooltip that says, "Current Keystone" and then a Mythic Plus dungeon name and key level. As long as the tooltip does not change this will be repeated indefinitely off the bottom of the screen. This has been happening since the launch of Dragonflight, but I couldn't narrow down which addon was doing it until now. As a workaround, I have turned off the above option for now.