I'm confused & don't understand

I, a transman, received this 'things that would get us fakeclaimed' tiktok from my bf, also a transman, because he was confused and didn't understand "transfem in transmasc body." I also do not understand and would love an explanation because my brain says if it's trans FEM in a trans MASC body doesn't that just make it cis?? Mind you this post was also included alters such as fictives, animals, and a fkn computer.