There is a wrestler, Khelif, who transphobes are getting angry at, for having elevated testosterone (even though she was on meds that lower T), and claiming she's XY. I don't know if the XY thing is true, but even if it were, it would be an inactive Y since she was born with a uterus and stuff.
But it reminds me of something interesting one of my professors mentioned years ago in college,
which is that it's likely LOTS of people have sex chromosome abnormalities and we just don't know it, because not everyone gets their chromosomes looked at. And a lot of early assumptions about sex chromosomes--like that it automatically leads to infertility or mental slowness and stuff--is likely biased because the only people getting tested were people who had some kind of health issue prompting the test.