Inability to use abilities after loading into game

This has been happening for a couple of months now. I'll be loading into game like any other game, however, once I've loaded into the game I will be able to right click around buy items and such, but the one thing I can't do is use abilities. I thought this was just happening to me, but as I heard my friends start complaining about it recently I thought I would post on this board. The only way to fix this is by restarting completely, but by then you are pretty far behind, and your team refuses to help because they think you afk'd. I just wanted to bring this it light, and see if anyone has a fix. This happens randomly, and there is no particular pattern, and there are no particular actions I do that cause this. Thanks for reading, and hope that someone can help me, or riot will fix this bug.