Luckily people are catching on and this isn't a common problem. The times when it does happen are fucked and a complete lack of judgement by all involved. Clearly transmen should not be competing against normal women, they are on a TRT protocol... Clearly transwomen shouldn't be competing against women, they have 20+ years of testosterone fuel'd bone development and as much circulating testosterone as their drug protocol is designed for, which is essentially enhancement.
Does make me mad when I read about it though. Fallon Fox for example is a fucking degenerate, she hid that she was born a man and absolutely dominated women in MMA.