Einstein for example complained about spooky action at a distance, but didn’t disagree with the results. “Quantum mechanics is very worthy of respect. But an inner voice tells me this is not the genuine article after all. The theory delivers much but it hardly brings us closer to the Old One's secret. In any event, I am convinced that He is not playing dice.”
So, he was completely on board with the results of the single photon double slit experiment and other observable results which are very odd. But, he may have favored non local hidden variable theories which are indispensable from QM and all it’s observable oddities.
Also keep in mind that the stakes are higher when it's the academic's core area of contribution which is under attack. Einstein's contributions to large scale physics were secure. If instead good we're playing dice at the scale of solar systems, threatening to obviate his primary contributions and consign his name to the dustbin of history, the reaction may have been a bit different.
So, yes some people will object long term, but it’s important to keep their objections in context. Plate tectonics is a slightly more recent revolutionary idea that actually converted most skeptics, but the early objections where reasonable and the actual conversion was quick once the idea approached it’s modern form.
Yeah, all I'm saying is that his total collection of contributions wasn't at stake here, so it was probably a bit easier to back down.
FWIW, my 'motivating anecdote' in this discussion is an old prof describing the earlier years of algebraic topology, which he had been very active in. There were apparently a number of older topologists who were pretty resistant to algebraization of the field. Which possibly had a lot to do with Poincare's attitudes about logic and proof.