Mouse Click Only Move Can't Attack

So, I got in a rank game, but when I started trying to attack a minion, the sword icon didn't show up, so I just moved to the minion. Same with champs; just move to them. I had to relog to fix it, but by then, the other champs got two levels on me, and their jg saw this and got me. Never had this happen. Anyone else having this issue with their mouse.