Sometimes the key tumblers in the doors seize from never being used. It happened on my F250 and we cured it by spraying penetrating oil into the keyhole. Then inserted and removed the key several times then started gently turning and wiggling. It finally broke lose.

Just two days ago my crossfires fob wouldn’t unlock the door. I thought the battery in the fob was dead. So I had to open the door with the key and thankfully it worked. Then after I started the car and drove it the fob was working again. Hopefully not a harbinger of a future failure…