This ones short but the mods settings do not automatically sync over server, even if someone is set female/other locally, the server shows them as male until they manually change, in which then it syncs over the server correctly.

to reproduce load a 1.19.2 fabric server, optionally modded, and bring a friend, everyone join the server, using anything but male presets, checking the gender tab displays them as male, reguardless how they look locally