A lot has been made, really, of the two "women's" boxers in the Olympics who appear to have XY chromosomes as manifested by their testosterone levels, as well as the 2016 Olympic women's 800 meters race, where all three medal winners had XY chromosomes, but presented externally as female. Wikipedia actually keeps a list of "intersex" conditions and "intersex" Olympic athletes. There are, interestingly, a fair number of them--I count 15.
So what do we make of this, statistically speaking? All in all, intersex conditions seem to affect about one in 5000 people, so fifteen people in the Olympics (or banned from them) in the past 88 years seems to be about right--there are probably about 50-70,000 individuals who have competed in at least one Olympic Games since 1976.
But that noted, if one walks through the list of intersex conditions, only a handful are the kind we're interested in; XY presenting externally sort of as female and with male levels of testosterone. If you've got one of the others, you're not going to the Olympics, and that's because you're going to be like me; just not that good in your sport.
The condition most likely is "5a Reductase 2 deficiency" and it's worth noting that the prevalence of this is unknown, and that its origins, genetically, seem to be a range of conditions as well. All in all, though, a certain portion of those with this family of disorders seem to have athletic strength and speed about 0.15 standard deviations greater than that of XX women, and about 0.85 standard deviations below that of males. The advantage may be somewhat greater vs. women, however, as there simply aren't that many of them. You're simply looking at a different portion of the distribution--there simply aren't that many people (thankfully) with this condition.
It's not a "trans" issue per se, and since it's "intersex", the sexual assault issues of "trans" and more importantly "fake trans" athletes in the locker room are not there. What does exist, however, is basic unfairness in competition--the best of these athletes appear to be on the level of good high school boys--and arguably a physical hazard in contact sports, especially combat sports like boxing.
What to do about it? The current approach since 2000 seems to be to wait until it's abundantly clear that there is a blatant unfairness or physical hazard. That's merely irritating with track & field, but dangerous to lethal in combat sports.
You're stuck, really, with either administering a sex test (swab for DNA in the cheek), or if one really wants to get some data, let's take some of these athletes to the weight room and compare bench press, squat, and dead lift with the ladies in their weight classes, and then to a medical lab where their bone density and skull thickness can be compared.
My bet is that the differences are not as big as that between unambiguously developed males and females, but it'll be statistically significant anyways. And the end result would be what we had prior to 2000; if you scored "XY" in your swab test, you competed as a male or not at all.