No, Einstein did not actually disbelieve in General Relativity Geometry. He developed the theory of General Relativity and was a strong advocate for it, even defending it against critics.
The misconception may have originated due to Einstein's initial hesitation and skepticism towards his own theory, as well as his constant efforts to improve and refine it. He also had disagreements with some aspects of the theory, but never rejected it entirely.
Einstein questioned the cosmological constant, which he initially included in his equations but later removed due to new evidence. He also had doubts about the existence of black holes, but eventually accepted their existence as a consequence of his theory.
No, Einstein's doubts did not significantly affect the acceptance of General Relativity Geometry by the scientific community. In fact, the theory has been extensively tested and confirmed by numerous experiments and observations, solidifying its place as one of the pillars of modern physics.
The current consensus among scientists is that General Relativity Geometry is a highly accurate and successful theory in explaining the behavior of gravity and the universe on a large scale. However, there are still ongoing efforts to reconcile it with quantum mechanics, as well as potential modifications to better explain certain phenomena such as dark matter and dark energy.