Certain Variable Font Axis don't operate properly

[JohnnyWestlake]

Typically Optical size never works along with other uncommon ones. Need to investigate why

[fdwr]

Can you think of any reason variable font axis might not apply for all axis? I assume my code is doing something untoward but I can't think of a reason some axis apply and some don't.

I'll need more details. I've played with a number of variable fonts where opsz and wght and ital all worked together fine.