Ffs. Any male, however he identifies should be changing in the male changing room. Let the men in there deal with that sort of stuff. Unpleasant as it is for them, they will be less intimidated.
Marks & Spencer is really showed their true colours. There is absolutely nothing stopping them nominating one changing room as a gender neutral one. The amount of times it will be used is minimal.
And once you stop the opportunity to be validated, or wank in a female environment, the changing room won't matter.
And yes, , it's been going on for years, now. As a result of transactivism.
M&S don't care about the protected characteristic of sex, but they might care about the protected characteristic of religion.