[GAMEPLAY] Sion - Respawn without working Q or R

Playing as Sion on Summoner's Rift, normal blind pick. Not sure what the trigger is - but it seems like after dying then getting a kill after death via my passive, once I respawn pressing Q or R does nothing.

I do not lose Q and R after every death; but I also don't get a kill after death all the time. At least twice in the same game I did die then get a kill and did not have the problem - but I was at lower levels. Not sure if level matters; or itemization; or opponents hitting me with higher level spells...

Had this happen in season 4; then okay for months since then, although I don't play Sion all that regularly. Of course; I tried to track my items and level for weeks to have more details when it recurred - and now it happens I had quit the record-keeping and have very few details.

I did play as Sion 1 week ago and did not have this problem at all - it is intermittent.

I left the game; and when I immediately returned after exit my respawn was completed and Q and R were working once again.

Then I died and again lost Q and R; unfortunately not certain if I got a kill after dying that time.

A second time, I left the game - and again when I returned Q and R were working; then my team lost.