Which is where the distinction, for me, is drawn between genderfluid and agender. Genderfluid is defined as “denoting or relating to a person who does not identify themselves as having a fixed gender”. But in order to flow from one to another, you have to believe in genders as real identities. I do not.
I too am agender, and basically agree with this distinction between being genderfluid and being agender or genderless. However, though I don’t have a gender identity myself, I do acknowledge and respect the genders of others as “real”. The gender identities of women, men, and non-binary people, whether cisgender or transgender, are real for them, whether I understand those identities or not.