Maximum Dex Bonus
This number is the maximum Dexterity bonus to Armor Class that this type of armor allows. Dexterity bonuses in excess of this number are reduced to this number for the purposes of determining the wearer’s Armor Class. Heavier armors limit mobility, reducing the wearer’s ability to dodge blows. This restriction doesn’t affect any other Dexterity-related abilities.
it actually says bonus when affecting armor as well. So by that logic it wouldn't affect AC. Though it's not unreasonable to for the DM to call that you are so clumsy that you literally walk into the attacks
