Minions not stopping agro

Every game that I start, I always notice one minion that is always agro'd on me unless I get completely out of it's visual area (however, sometimes this doesn't happen and it follows me everywhere). It usually happens whenever I get too close to the minion wave and the agro will never drop, no matter what I do (moving away, hiding behind my own minions, have a ally attack it, anything I usually do doesn't work). However, it only happens during the start of the game and I don't really notice it happening again.

It might be happening again, but I'm far too invested in the game to notice this later.