[GAMEPLAY] Sion Q and R randomly stopped working

Just finished a game about 15 minutes ago where, after 30 minutes in, I was playing as Sion and my Q and R stopped working. This happened right after a death. I tried dying again, alt-tabbing, re-connecting, rebinding my hotkeys, nothing seemed to work. Talked to the other people in the game, and no one else seemed to have any idea what the issue was. My W and E were working fine. Tried to recreate it, but no real idea on how or why it happened. I was killed by Vayne + Blitzcrank + Jarvan, and all of them used their ults within 5 seconds of me dying, but that's the only thing that seemed odd. If I hovered over the icons, it would show the range, tooltip, etc., but I couldn't click on them or hotkey them.

Thank you for your time and consideration! It was very sad, as we started to lose after that - half your skillset disabled (particularly some of the CC), makes for losing game :(