I believe that all the above explained is correct.
One more factor to consider:
All references to pilot seat.
Always to the right because there is a force yawing the model constantly to the right.
This could be anything: crossed trim (right rudder fighting ailerons), elevator non-parallel with wing (elevator-rudder twisted to the right), twisted fuselage, engine thrust to the right and down.
When the elevator forces a higher angle of attack of the wing, it reaches a velocity beyon which the lift disappears suddenly.
Leading edge, airfoil, cover, warp, etc. may cause the right half of the wing to reach this critical point (stall) first.
After that moment, you are flying a model that has only a left wing, and a parachute (lots of drag) on the right side. There you have that one force yawing to the right, probably helped by the other.
The model starts rolling to the right and falling nose first, helped by the advanced CG, while the left half keeps flying, helped by the increased air speed.
Test the snap at sufficient height and under power first, and then cutting the power right at the moment of feeding elevator. If there is a marked difference, reduce right and down trust of the engine.
When your wings are heavily loaded, due to elevated weight of the model or/and advanced CG, the stall is reached at higher speeds and lower angles of attack (high speed stall); that is what makes this model perform differently from the 3D you have.
Move the CG as aft as you can, and remove weight from the model.
Good luck!!