AnimInstance override blending

Trying to implement a new weapon system using animation blueprint overrides.

Currently the weapon has a stance, so the anim blueprint know the pre-defined stances and using blending, depending on the current equipped weapon stance value.
Now i made a basic blueprint and an override blueprint for each stance.

After switching weapon, in the character class i call the code below to change the anim instance, but the state is lost.
So there is no blending between the old and new instance, like it would be with a state blend.

	auto animationClass = GetDefaultAnimationClass();
	if (CurrentEquipment != nullptr && CurrentEquipment->GetCharacterAnimationClassOverride() != nullptr)
		animationClass = CurrentEquipment->GetCharacterAnimationClassOverride();

Anyone using a simular system or has example on how to blend between old/new instance?