I am confused with platy sex determination

Recently I crossed blue tuxedo female and white mickey mouse male.
After raising 1 month some of them showed slight tuxedo pattern and others not.
And those showing tuxedo was male and others seemed female.
So I thoght female was WY(Tuxedo) and male was YY.
But thesedays those seemed female became manly.
They came to have small gonopodium which they can move just like males do.
What is happening here?
I thoght femalising force of W was weak or the female was just X(non tux)X(tux).
In the latter case why there was difference in the time they have gonopodium and also difference in the size of gonopodium?
And is there any possibility that this F1 fish could breed?

fish with smaller gonopodium like object(no tuxedo)

male(hetero tuxedo)

When it comes to phenotype, it doesn't say that the genotype is the same. So, if you don't know the if one or both specimens used are pure bred ones when it comes to a strain, other phenotypes may occur in the offspring. And if the female was already storing sperm packets of another mating instead of this male, the offspring can be fathered by a different male than the one that's in this current tank.
When I try to crossbreed platies or a different kind of livebearer, when it comes to females, I only use virgins to be sure that the male I use will be a 100% guaranteed the father. And of course, I need to know the genetic background of the father to be.

And again, phenotype can be different from genotype.

Yeah you are right.
As the children all possess two characteristics that are only seen in the male not in the female(namely orange dorsal and mickey mouse), I thought it is very likely that the fish are all cross of the two parents.

Try this book to explain

Today I learned something called P genes affects maturing age of platy.
And penetrance affects macromelanophore pattern that even fish with macromelanophore gene on sex chromosome doesn't show it at all if penetrance is zero.
Maybe these two things had to do with my problem.