Gameplay, can't auto attack as sion

So i was playing nexus siege, and the other team had a Azir. I saw him trying to escape and i alted toward him and he alted me at the same time so my alt count it as a wall and did; but the after effect is the bug. The game still thinks you are alted and dosen't allow you to auto attack. I found out the way to fix it is by just using a ability or just back and it'll fix but i couldn't figure that out until 20 seconds later.