Einstein's General Theory is internally inconsistent because it adopts SR's flat-spacetime Doppler equations.
These are incompatible with gravitomagnetism. The field of a moving gravitational source appears asymmetrical along its motion axis - it pulls more strongly when it recedes than when it approaches. This alters the momentum and energy of light, generating a gravitomagnetic shift that is red when the body recedes and blue for approach.
Either way, relative motion between strong-gravity bodies must generate a different Doppler relationship to SR's.
But since all bodies in the universe are compelled to obey the same Doppler equations, all bodies must then obey non-SR relationships –we are not allowed to have different Doppler relationships for strong-gravity and weak-gravity objects.
Also, since medium-strong and an extremally-strong gravity-sources must all show the same Doppler relationships, the equations of motion that we obtain for a black hole (most extremal gravitational body) must also apply to every other sort of body, down to individual hydrogen atoms.
So the theory of relativistic gravitation (and/or a valid general theory of relativity) cannot reduce exactly to SR physics, and all relativistic physics needs to be compatible with the "black hole" solution (maximal relativistic deviation from SR). Are you finding that your project is producing this same result from other arguments?