Happened to me as well.
MatchID: 1029424112
Happened quite quickly, think I was only able to throw 3 or 4 potions before it happened.
I use normal casting mode
No special keybinds, I'm on the ps4
I had a potion stored in the consumable slot. Either pressing the skill or using the potion just made it swap potions.
Also, there were 2 baba yaga's in this match. The enemy baba yaga seemed fined and threw potions throughout the match, me (player name CupOfNoedles) wasn't.
Gonna copy/paste this to a lot of people - unfortunately Reddit isn't great for individual responses.
As an update we shipped a fix for this to Xbox/PC/PS4. It was a client fix, and server didn't need a restart, so you'll have to relaunch your clients to get the patch (was sent out at ~1pm EST) . Let me know if you run into this issue again after you've downloaded that patch!