Okay so it’s not against a wall staying warm and it’s not runty with no leaves! It is very lush and pretty… which isn’t always so good.
New idea: too much vegetative growth? Stop fertilizing it?
Also, I would agree that a big drop in temp or temps <-10F will kill peach buds. But every year for four years seems… unusual. And reliance is known for being hardy.
Here is some light reading for you:
Hopefully some folks with more knowledge than me chime in soon! I’m out of ideas!