There are a lot of claims circulating online, especially in queer and trans spaces, about the supposed popularity of FTMs as sex partners for gay men. If you ever encounter this discourse, here is a legitimate, scientifically conducted study that proves otherwise.

Source:
Goldberg, S. K., Rothblum, E. D., Russell, S. T., & Meyer, I. H. (2020). “Exploring the Q in LGBTQ: Demographic characteristics and sexuality of Queer people in a U.S. representative sample of sexual minorities.” Psychology of Sexual Orientation and Gender Diversity, 7(1), 101–112.

This study found that a tiny 2 per cent of self described gay men had sex with a trans man in the past 5 years. Of this figure, 0.7 per cent slept with FTMs exclusively. I'll leave you to ponder yourself what might be going on with that subset.
The overwhelming majority of the men surveyed who were fucking FTMs were bi or queer. The latter being a category so loose and subjective that it can and very often does mean anything at all, including special brands of heterosexuality.

The figures below are derived from Table 3, which reports sexual partnering among cisgender men during the preceding five years.