character walk to enemy base with mouse click

I just logged into Lol and started a game of co op vs ai beginner. I selected Nasus to play like always. The loading time too a while but nothing about that. Once the actual game loaded up, every time I click the mouse to walk somewhere Nasus would auto walk to enemy base for some reason. Basically the line you see on your mini map would go to the enemy base and past the nexus. I used the B button to recall back to base, that was the only was to make him stop walking. I have tried to click other places but it didn't help. This is the second time this had happen it may be a bug or just my net but I'm not sure. I had to quite the game sadly because I could not help in any way, resulting on temp ban. Oh and reconnecting didn't help either.