My father threatens to disown me because I choose to grow my hair

Assalamu alaikum dear brothers and sisters. As the title mentions, my father is talking about disowning me because I am growing my hair longer. He says my younger half-siblings, aged 12, 9, and 6, might think it's okay to disobey him, and he wants to set an example that we must always obey him no matter what, as Allah commands. I completely agree that we should respect our parents and not be a bad influence. But growing hair is not haram-he even admitted it's not haram, just disliked. My parents divorced when I was born, and my mother is also Muslim but more lenient. Is it permissible for a parent to cut ties over something like this? I'm an adult, but I'm staying with him for a while because my mom thought it would be good for us to spend time together since we haven't lived together much. May Allah bless you all, ameen.