Autofill protection counter includes remade games.
When you play support/fill once, you are supposed to be guaranteed your role for 2 games.
In this case, I played Nami support and got autofill protection. I attempted a game as Nocturne top (ye I know shut up) but before anything happened the enemies remade. Then I played a full game of Nocturne top and the autofill protection was removed. I only played a full game and a 3 minute game which isn't supposed to count for anything. I'm not sure if this is a bug or just something Riot never thought about.