[GAMEPLAY] Unable to use skills on sion

In a dominion match i was playing earlier i was playing sion and then after i died a few times using some of my skills before dying and going into my passive form i couldn't use them anymore even though they were off cooldown. i was unable to use my Q and R the entire game and some of my teammates harassed over my performance because of it.

1. While alive with sion charge up your Q or use an ability before dying
2. respawn and try to use the ability and you wont be able to
3. try to do the same with other abilities and they will become disabled

this isn't the first time ive seen it happen on sion or other champions. here is a dunkey video where it happens to him at 1:24.