The plane stalls flat. May be too centered forward ?
I think that alone is not enough. That plane should fall out of the sky and crash. This is no Carf Eurosport with Vektorunit. It is a F-16.
The fact that I have full rudder controll while having the nose pointed right up says a lot too. How do those rudders work without any air going over the surface? This works with a 3D prop plane because of prop wash but definatly NOT on a jet without vector nossle.