Is the plug securely clipped to the cord on the rhp? I’ve got 4 pro heat RHP in three sizes and have had no issues for over three years. The plugs can be a bit stubborn to clip shut though. Had to use a pair of channel locks to secure a couple of them
This right here. The plug is a pain to secure.
Even if you do have a more serious issue with the panel, Bob will take care of you.