Problem with Gastrodon

[RyuuShin]

today i tried to make a east Gastrodon.
The problem is that legality checker tells me the gender check is invalid.
I tested and took a 100% legit Gastrodon file and changed it from west to east form
which made the gender check show invalid and is still if i change it back.
Also i tried to alter the PID by selecting a diffrent Type 1 PID which also made the gender check invalid.
I dont know what to do here.

[CNash]

Attach the PKM file to your message and I'll see what I can do.

[RyuuShin]

Here it is.

[CNash]

I've hit a brick wall; I don't know enough about what Legal looks for in Gender Check to know what to change. However, simply making your Gastrodon male allows it to pass Legal. Since it's a hatched pokémon, you don't need to worry about PIDs, just flip its gender. Gastrodon has no visible gender differences.

[Patchworks]

anytime a pokemon fails a gender check. It's USUALLY because you somehow had both gender flags ticked. It's happened to me before. Just do what CNash suggested

[RyuuShin]

Interesting that making it male makes the gender check legal.
Does esomeone know what actually is checked with the gender check ?
I actually tried using some PIDs which are 100% female but still its illegal.

I know a male one would look exactly the same.
But i am kinda a perfectionist and i am curious whats the case here.