Mom never believed me about being Bi?

I’m 32 and have been NC with my mom for about 4 years. Growing up I always knew I liked both genders. There was never a question and for me it was quite natural. I tried to tell my mom when I was about 9 but she talked me out of it and told me I was just interested in their fashion. I told my bro when I was 17 and he accepted it. He then randomly told my mom one day and she just said ‘mmm;’ and that was it.

Then one last time in 2020 I tried to tell her again. Keep  in mind I’d been partying in gay bars for a year and was in a LGBTQ friend group. I told I’d kissed a few girls and she just said ‘I don’t think you are’ and again that was the end of the convo.

Not sure if this is a NMom trait or just because I only ever told her about the 1 relationship I had with a guy.