With the original smaller diameter bead, the impacts should be centre of the bead. Since the night sight is larger in diameter, the centre of it, where the bullet is supposed to strike is actually higher than with a smaller diameter bead's centre, thus making this sight actually shoot a bit lower than the normal front sight. As you will automatically drop the muzzles to put the centre of the larger sight on the 'spot' to be hit, a lower bullet strike is quite likely.

Due to using the normal use of a night sight at close range, this elevation difference would not be noticable. I believe it would indeed be a good idea to attempt to repair or have someone repair the front sight. Trying to shoot any range at all past close range with the night sight might be difficult and perhaps frustrating due to low impacts. Much of course, depends on the loads, bullet weights, regulation, etc.

Good luck.