Certain channels not coming back after commercial breaks

I am using the xfinity stream app on a FireTV. Some channels, specifically TBS and TNT, will work fine upon starting the app, but after one commercial break the broadcast never returns and the screen just sits blank.

I have tried switching channels, force quitting the app, clearing the app cache, uninstalling and reinstalling the app, and restarting the TV. Restarting the TV occasionally works, but the issue reoccurs with the next commercial break so this is not a reasonable solution.