I have had regulator diaphragms go bad and had to replace them. Well, had a guy at the welding supply shop replace them.
I went through a bunch years ago. So many that I always kept a spare regulator. We would always turn the regulator key at night to close the diaphragm and close the tank. Then in the morning, open the tank then adjust the key to the desired pressure. That pop of pressure from opening the tank seemed to be what was wrecking the diaphragm. For many years now I never touch the regulator key. I just close the tank. That eliminated my problem.