registering AnimationEvent leads to inability to block and/or attack

[ChaosWarrior]

As in the title the issue is that when I register NPC for animation event, then player is loosing ability to attack or block (or both). Is there way to somehow make it work?
At first I noticed this while I was experimenting with a spell effect that makes you fire things like with bloodskaal blade, and now I was registering things to detect if NPC was doing some ranged attacks or just standing.
So the code is in magic effect, I apply spell with console command "cast", notifications show that events firing as expected.

actor trg
int i = 0

Event OnEffectStart(Actor akTarget, Actor akCaster)
	i = 0
	trg = akTarget
	registerforsingleupdate(5)
	if (RegisterForAnimationEvent(trg as ObjectReference, "MRh_SpellFire_Event") && RegisterForAnimationEvent(trg as ObjectReference, "MLh_SpellFire_Event"))
		Debug.Notification("registered")
	endif
endevent

Event OnUpdate()
 	registerforsingleupdate(5)
	i = 0
endevent

Event OnAnimationEvent(ObjectReference akSource, string asEventName)
  if (akSource == trg as ObjectReference) && (asEventName == "MRh_SpellFire_Event")
		i+=1
		Debug.Notification(i+"# MRh_SpellFire_Event event sent!")
  endIf
  if (akSource == trg as ObjectReference) && (asEventName == "MLh_SpellFire_Event")
		i+=1
		Debug.Notification(i+"# MLh_SpellFire_Event event sent!")
  endIf
endEvent

Event OnEffectFinish(Actor akTarget, Actor akCaster)
	UnregisterForAnimationEvent(trg as ObjectReference,"MRh_SpellFire_Event")
	UnregisterForAnimationEvent(trg as ObjectReference,"MLh_SpellFire_Event")
	unregisterforupdate()
endevent

UPD it seems to affect player's controls when PC is one who casting, like ">player.cast 1413069f 0005054a left" when doing like ">cast 1413069f 0005054a left" it works using selected reference as caster. But still weird bug.