Mouse/Keyboard glitch

Two games in a row now Ive had a bug where I can't buy items from the store or even hit esc to pull up the menu to quit and attempt to fix the problem. Not only does it not let me buy items but it changes my right click (movement) to be on auto attack only. So If i ever get into a fight and try to run it just keeps attacking because its on AA closest enemy (the red marker). Its quite annoying it takes away from everyone else cause i have to close the game and relaunch completely. Twice its happened and there seems to be no answer anywhere I search. The first game I didn't pay attention to when it happened, the second time I noticed it happened when I had the chat up and I was clicking away because a person was trying to engage me while I was typing. Once again no clue how the bug initiated or what caused it, please help me someone cause its quite annoying. Ive tried switching my mouse, disabling my firewall, etc... Any information will be greatly appreciated.