Adaptive Armor Bug

So I was in a practice bot game with Nasus, and I look at my armor and magic resist... and they are both switching between two numbers: 162 and 202 for armor and 145 and 167 for magic resist. The only thing I can think of that would do this is the Adaptive Armor mastery because its converting bonus armor to magic resist but reverting for some reason, but the mastery triggers again and tries to adapt again. And this went on for the rest of the game.