I know what you mean about being attracted to the masculinity of trans guys. I have been told more than once by people attracted to trans women that it, in part, is our femininity that attracts them.
I am not telling you about the feeling of invalidation to make you or anyone else feel bad, and I hope you didn’t take it that way. I just want to present another perspective. At the end of the day, it is really no one’s business why you are or are not attracted to someone.
Remember, too, that there are trans men with penises (although fewer trans men seem to have bottom surgery than trans women do).
I appreciate your responses.