Leave Buster unexpected bug

When I enter Training Chamber, why I try to stand still to activate my innate ability, why Leave Buster kicked me out of game. When playing match, some champion like Teemo need to stand still to hide from enemy champion and Leave Buster kicked me out. When playing Singed, I entered the deeper base of enemy to harass minion and when the enemy come there for react, I hid in the bush to wait for them to leave, why I also be kicked out of game room.