Hmm, that's weird >.< It's definitely a working feature on my end as I've tested both masculine and feminine voice routes with default MC name + chosen name + all pronoun sets multiple times without any issues T_T
Which version are you playing? And what point have you gotten up to? :o
You can't select a name or pronouns until you get past the opening scene where you choose a voice for Blythe.
(Basically, once the black screen with white text disappears and you are in your bedroom with Blythe, Blythe should then ask your name and pronouns shortly after you wake up.)
To choose your name, you have to pick the option "It's embarrassing" instead of "Bunnie" when Blythe asks you what your name is. Then it will allow you to type in a name of your choice :3 MC will ask if they can be called that instead, and Blythe will agree. It doesn't really matter all that much though because MC's name never appears in the text box since they have their own unique yellow text box anyways, and even if you rename MC, since the game is voice acted, Blythe will just refer to you by pet names like rabbit, bunny, silly, etc. Anyways :3
No worries :3 It's my fault for not making it very clear >.< I should maybe have put in brackets or something next to the choice (rename MC) or something like that so that players know to pick that option if they want to rename. Sometimes I have a habit of forgetting that just because I know something, other people can't read my mind and know it too x3