Same issue on my '14 Sierra. Our Enclave, Jeep and the remotes that came with the opener will get the job done from out in the street (60' Driveway). My new truck only opens the door half of the time and then, the truck has to be just inches from the door (thank goodness for parking assist). I've never had success down the on the street or in the driveway.
I took the truck to the dealer today and was questioned if I properly "trained and learned" the remote to the truck then the truck to the opener. Obviously I did since it works occasionally. One of my "We Owe" items requires a part to be ordered so when that arrives, they're going to check out the transmitter. I'm a little concerned because the service writer didn't seem too optimistic about the fix.