Stuck in T-pose while fighting Mektul

This bug is kinds funny. Happened to me a few times now. While fighting [Mektul, the Forgemaster] animations stop working. My char gets stuck in a T-pose and zoons around like I'm lagging really hard. At first I thought it was lag, but reloading the area shows no connection problems. Mostly firing [Ember Fusillade] and [freezing salvo] with splinterheart. Also Raging spirits.
Because I tried experimental build, I fought Mektul before (when I first encountered bug), couldn't beat him in time and now went back and got the bug again.