2019 Sierra. Ok, borrowed a friend's trailer. One of his lights was out. No big deal used it and returned. Now I get the fast blinker, so I think my truck has a light out. But all lights work fine. Go to trailer app and it says "Trailer Connected Check Right Taillight ". No trailer on truck? I checked fuses, removed all trailer profiles, parked truck for a few hours thinking it may reset. Still says same. Unhooked battery. Still same. Connection to my trailer that worked fine prior and now nothing? But still showing same "Trailer Connected Check Right Taillight ". Wtf?