my 13 pantt sometime the auto unlock doesn't work. (when walking up to vehicle with fob in pocket) is this the sensor right on the handle?? dealer told me its part of handle part #97053796100g2x and also have to be painted

 

I would think the RF portion is internal to the car, have you tried other doors to see if it happens with then as well?
have you tried changing the FOBs battery? there is a touch sensor in the handle that could be going bad.

 

The next time it doesn't unlock, try using the key in the fob to manually unlock the car. Then relock the car and see if all works ok from that point forward. If it doesn't, it is most likely the actuator inside the door and there are youtubes how to remove and replace it.

I've had the same problem and the metal fob key did the trick, but today I learned that if I open the hatchback when the car is locked, the drivers door will not unlock. If I never open the hatchback when the car is locked, the drivers door always unlocks just fine. Looks like I may have to replace the actuator afterall .