On the other hand, as you dont know about when he is with Katie, it might just be the case.
You cannot have it both ways. I remember her taunting Junior when he was smaller.
I do agree that she is good with Harvey.
I think the issue is more to do with the fact that PA allows his kids to filmed which subsequently is causing them, more so Junior to show off in front of the cameras, as another poster pointed out there have been reports of how well behaved they are under normal circumstances so the solution imo is simple, remove them from there Dad's show.