This kind of inconsistency is expectedly inevitable because of contradictory principles, Einstein's equivalence principle that requires space-time coordinates have physical meaning and the "principle of covariance" that necessarily means that coordinates are arbitrary, are concurrently used in Einstein's theory [11].
Zhou [21] is probably the earliest who spoke out against the "principle of covariance" and he pointed out, "The concept that coordinates don't matter in the interpretation of Einstein's theory necessarily leads to mathematical results which can hardly have a physical interpretation and are therefore a mystification of the theory." More recently, Morrison [12] commented that Einstein's "covariance principle" discontinuously separates special relativity from general relativity.