Sims All Born with Same Coloring

This is a really weird glitch I've noticed in my current game. For the children that sims have, regardless of if they're in my active household or just townies, all the sons will have the same hair, skin, and eye color, and all the girls will have the same hair skin and eye color. So in one family all the boys have hazel eyes and dark hair, and all the girls have green eyes and a different shade of hair. Is anyone else having this issue? It's not that big of a deal it's just a weird thing that's been happening to me.