If enable Preview Slot of non-default slot in AnimMontage, AnimNotify of AnimationSequence does not run.

void UAnimSingleNodeInstance::SetAnimationAsset(class UAnimationAsset* NewAsset, bool bInIsLooping, float InPlayRate)
{
...
Proxy.ReinitializeSlotNodes();
if ( Montage->SlotAnimTracks.Num() > 0 )
{    	
   // add
   for (int32 i = 0; i < Montage->SlotAnimTracks.Num(); ++i)
   {    		
      Proxy.RegisterSlotNodeWithAnimInstance(Montage->SlotAnimTracks[i].SlotName);    	
   }    	
   Proxy.SetMontagePreviewSlot(Montage->SlotAnimTracks[0].SlotName);
}