[Audio] Strange sound muffling when playing Shen and using Q

This is a very strange bug I have experienced 3 times in a game today in patch 6.6.

Every sound would have a 'muffled' effect (as if I'm under water or something) after casting Q with Shen. In my last game it happened on 3 separate occasions, mostly while in lane vs a Mundo. On the third time I tried messing with my headphone wire to make sure it wasn't that but it did nothing.

I'm not sure it was on cast or when retrieving my sword.

I'll keep playing to see if it happens again.