Small modding question, polygamy

[Karkhel]

Some time ago I made a pretty small mod that just changed christianity to include polygamy, it worked for women too despite gendered law being male preferred, since then I have shuffled some mods around and I cannot recreate a setting where this works like that again. it worked without cultural polygamy. What is needed to have working female ruler polygamy while gendered law is male preferred? I'm still playing on version 1.18 because not all of the mods I want are updated properly. I usually start as bohemia and a custom ruler if that matters.

00_christianity.txt 20_doctrines.txt