The funny thing about that is - it's a solved problem. The reason you heard about it for a while is that they hadn't tightened up the rules yet. As with anything, problems are highlighted, they are studied, and new rules are put into place to account for what was learned. Right wing media of course discovered a boogeyman that was so useful they will be using it for years still, even if it doesn't exist.

It wasn’t a problem to begin with. Meta studies recently showed trans women have no biological advantage over cis women after HRT, certainly nothing than cis women don’t have biological variation within anyway. All the rule updates did was exclude and further marginalise an already marginalised extreme minority. There are very few trans women to begin with, fewer of us still are competing in sports. Nothing was studied here, the people who made the rules aren’t scholars, they’re bigots. They’re using us as a distraction from their poor governance.