Hey, thanks for the ton of feedback!
First, can you upload your save files somewhere so I can track down that bug? They should be in your Users/<USERNAME>/AppData/Roaming/RenPy folder, and that would be very helpful to reference to fix this.
The changelog has a lot to say about why Zach doesn't just accept himself as a woman so early on (Ctrl+F from "This is as good of a place as any to state that").
If you want more context to see how Zoey would end up accepting herself as a woman and don't mind spoilers, the entire Britney outline has been made public and is written in very full detail.