Darn, I wish you posted a fix to this. My 2020 2500HD is only 3 weeks old and all of 600 miles and the FOB stopped unlocking the doors today.. It started when I pressed the unlock button twice and hold to roll down all 4 windows. Then I started the truck and moved it only 50 feet, killed the engine and the message popped up "Remote Not Detected " .. I didnt think much of it, went in the house, 5 hours later when to remote lock the truck and nothing. Thought maybe the battery was dead so I replaced the 2032 battery. Nope, no lock the doors. Went to the truck and message indicated that remote not detected. Put the remote in between the cup holder and the truck will start. Kill it and it puts up the message Remote Not Detected. Gave up and lock the doors by hand and decided to sleep on it, and post on here hoping someone has had this happen with a solution.