So I cast hold person on a mob and he fails his saving throws. His turn comes up and he passes it and is allowed to act. This seems wrong, you should forfeit your next turn on a failed savings throw other what the hell is the point of the spell.
It's because they all roll their saving throws at the start of a round, and if they succeed, they get to act on that turn too, for some reason. Definitely not how it's supposed to work, and it really needs to be fixed.
5e hold person allow for a save at the END of affected creature's turn, then if successful the spell ends and the creature can act again in your next turn. Save at beginning is just a dumb nerf