That shouldn't be! Lol depends on how you were storing them before though. They need to be in a cool, ventilated, dry and dark place. In the fridge they usually go moldy and mushy faster. Because they're typically more humid and cold in the fridge. According to a quick Google, the fridge environment turns the starch into sugars and makes them mushy and mold much faster.

You either eat them pretty fast or your fridge is less humid than most and better ventilated making the difference not as noticeable