I think I figured out why my LG G4 fails some of the time. I think if I left it in my pocket for a while (>5 min), when the proximity sensor is covered, it somehow disabled part of the bluetooth. If I just take the phone out of the pocket, it will work. If I just put it in my pocket, walk out the house door to my car in under 2 min.. it will work. I tried turning off the battery optimize on the Tesla app and it didn't seem to help. Pretty much I just need to hold my phone instead of leaving it in the pocket.