I don't believe trans women are men, so I don't have an issue with them being in women's spaces.
That may be your belief but you are factually wrong.
Humans cannot change sex, any more than any other mammalian species. Sex in humans is binary and immutable. Transwomen are adult male humans who declare themselves female, which is impossible. Whatever they call themselves, however they present, they are adult human males, and the word for such people is men.
Some people believe that the Earth is flat, but they are factually wrong.