[GAMEPLAY] Attack only mode?

So in some games of REAG OF REGENDS I get this bug where I can only attack. I can move and its like im always holding ctrl + a for auto but I dont ever use that. Anyway im on a mac maybe thats the issue. I've never had this issue on my PC, so im assuming its a Mac client bug. It happens randomly and I dont know how to reproduce the bug. I do remember in one of my games that my auto attack animation went off and the auto left my character but it did no damage and then the bug reoccured. It seem to only happen on ranged champions. I can fix the bug when I reconnect to the match but thats not a thing I would like to do often. This type of bug has only happened to me 3 or 4 times in the last few months. I would just like to have this fixed so that I don't have to deal with this anymore.