I've had several GFI outlets fry because of lightning strikes. Sure the whole house is grounded, but a direct hit, or even a pole strike will blow out the screen on your TV and fry the computers and phones as fast as...... Well..... Lightning.
I lost 2 well pumps in one summer to lightning. The...
I noticed, just by reading the OP, that the fridge is question is "new".
Here, let me C&P it for you.
"New house. Garage has a 20 amp breaker with 5 outlets counting the garage door opener, on it. One outlet has a 20 amp GFCI outlet in it which is required by code? I have a spare refrigerator...
I have found that GFI outlets are often eh-hem..... faulty.
Like VenRed says, try it on a different outlet. (I'm not sure extension cord is the best way to get there though)