Whats wrong with his comb please?

[BokBokBeginner]

I am assuming Max has one pea comb/blue egg gene combo, and one not-pea/not-blue.

That would give you:

Crossed to your Araucana, Easter Eggers, some of them with pea comb and some with combs like Max (but all laying blue eggs or possibly green eggs).

Crossed to your brown-egg layers, you will probably get about half Easter Eggers, with combs like Max and laying blue or green eggs, and about half with single comb who just lay brown eggs. The ones that lay brown eggs I would probably call mixed-breeds but not Easter Eggers. (Comb exception: with a Wyandotte mother, rose comb instead of single comb, or cushion comb instead of comb like Max.)

With your Araucana-cross pullet, probably half Easter Eggers with combs like Max, a quarter Easter Eggers with proper pea combs, and a quarter with single combs that lay brown or white eggs.

If you want a variety of shades of eggs, Max sounds like a reasonable choice.
He might even be a better choice than a pure Ameraucana, if you want a mix of browns as well as blues & greens.

If you want specifically blue or green eggs, he's less good, but still better than a pure not-blue-egg rooster.

And if you cross him to your Ameraucana and keep a son with a proper pea comb, that son is likely to be pure for the blue egg gene, so as good as a pure Ameraucana for purposes of breeding colored eggs.

Thank you NatJ yay Max can stay that is exactly what I want a mix of colours greens blue, even browns and whites.
Thank you so much for taking time to explain all of that to me I am super excited now!