PostEditChangeProperty doesn't get called?

I made a custom animation graph node

UAnimGraphNode_Custom : public UAnimGraphNode_Base

with this UPROPERTY

UPROPERTY( EditAnywhere, Category = Settings )
FAnimNode_Custom Node;

Inside FAnimNode_Custom I have this

UPROPERTY( EditAnywhere, BlueprintReadWrite, Category = Settings, meta = ( PinShownByDefault ) )
mutable int32 NumAdditiveAnimsUsed;

I’ve added

/*public*/ virtual void PostEditChangeProperty( struct FPropertyChangedEvent& e );

to both FAnimNode_Custom and UAnimGraphNode_Custom and neither of them get called whenever I modify the NumAdditiveAnimsUsed variable in the editor, what else do I need to do so I can get the callback ?

PS: Currently using UE 4.7.2