Was there any non-star wolves you were breeding beforehand? (whenever that was) or were you only breeding 1 & 2 star? I know, because I let mine freely roam as introduced species & their population grow because they kill & eat everything that moves & breed from the meat drops (neck tail, boar meat, deer meat) and self sustain.

Otherwise you would have not as much of a mixture of no star & star pups. Are you running any mods or anything like that?

I know if you cross breed a 1 & 2 star they usually always have a star pup-cub. No star & 1 or 2 star can be a % chance random whatever the cub turns out to be.