It’s an easy test while the boat
is out of the water
to check for bend. Set up a fixed point almost touching the end. Rotate the shaft, if it moves relative to the fixed point, it is bent. This should have been done by the people replacing a bent prop. It takes them minutes. If they didn’t they are ignorant or sloppy.
A good machine shop can straighten a shaft as good as new.
It could be the reconditioned prop is out of whack and the shaft is ok.