Mac Problem: Cursor Stuck on A-Attack, can't buy items, can't use "B" to teleport home

Usually late game I lose the ability to right click. My cursor gets stuck on A-attack and so you simply run into minions or champions and there is no way to stop it. Also I lose the ability to teleport back to base. Similarly, I can't buy anything in shop. Sometimes it resolves it self, others I just end up dying repeatedly until the game is over. I've had discussions with friends with Mac and this happens to all of them. Has riot addressed this? I've asked for technical support and I'm always told to re-install which never fixes the problem. The game is unplayable like this. It's a huge bummer. Others experiencing this?