I wouldn’t say bisexual makes sense categorically for anyone who dislikes half of the masculinity/femininity spectrum.
Bisexual is simply someone that is attracted more than one gender. Nothing to do with masculinity or femininity, so in this case, as I said, it’s a perfectly acceptable label. But if it doesn’t help the OP navigate the world or understand themselves, then it’s not the right label for them. If gynephilia does help them, then that’s the right term.