Quite, as I said, they are problematic on the TWAW front and yes on prostitution being harmless sex work, both positions I completely disagree with. However, you'll be hard pressed to find a union that didn't officially hold those positions. But as I said, the reason I didnt choose GMB is their particularly close relationship with Labour/Momentum.
However I do see, through my fmaily memebr and his colleagues, that many of them also dont really believe in the TWAW position and are increasingly fruatrated by men cheating in women's sports, and they tend to focus more on helping individual members who are being railroaded by large organisations.
That's why I joined a union, for selfish reasons to do with my particular work context, but you'll never find one that isnt also problematic to a feminist position.