Random Gray Rectangle

Hello…I’m using Kodi 17.0 with a Firestick 2 and everything is generally working great except for one very annoying problem. Randomly and frequently a gray rectangle appears on the bottom right of my TV screen, and remains for random amounts of time, very brief to many seconds. It appears to be some blank notification box, but I haven’t been able to figure out what it is or what causes it. My only thought is to delete and reinstall everything, but obviously would like to avoid that. Any help would be greatly appreciated…thanks.