There is no right or wrong way to behave as a man or a woman. Your sex in no way dictates your attitudes and feelings and behaviors, so I struggle to understand how a person could feel “gender fluid.” It requires a stunningly black and white view of gender behavior.
Believing in this nonsense requires believing that being a “man” means being macho and butch and manly at all times, and being a “woman” requires you to be sensitive and soft and romantic at all times, and that any behavior that transgresses that divide makes you trans or fluid or whatever.
Believing in “gender fluidity” ironically requires an incredibly rigid view of sex and gender roles/norms. It’s a belief system that is fundamentally regressive, not progressive. It’s the bizarre intellectual marriage of modern wokeness with 1950s-style gender norms. It is a bizarre and stupid mentality.