That is in fact inaccurate. There are one or two liberal mosques in all of the UK which allows mixed sex worship.
28% of UK mosques don't allow women in. That is why there is a longstanding UK campaign called Open My Mosque for women to actually to be able to get in a mosque.
In most of the rest of the mosques women have far smaller and substandard facilities which are always segregated.
There are a small number of modern mosques which there are equal facilities, but still segregated and women are allowed positions in management. I don't like this segregation, but separate but equal is the bare minimum, but it still contradicts the basis of their religion and I am going to always point that out.
Take a look at this pitiful list of UK mosques with separate areas for women remembering there are around 1700 mosques in the UK:
https://www.amaliah.com/post/68657/uk-mosques-taraweeh-spaces-women
Bear in mind this is in the UK the situation in many Muslim countries is worse. Of course some Muslim communities the situation is better. It is clear from basic scholarship that in the days of the Mohamad there was not sex segregation in worship and women had a higher status. This is still seen in the pilgrimage to Mecca where there is no sex segregation.
The first mosques in the UK in Victorian times had no sex segregation and had women in leadership.
https://www.mdpi.com/2077-1444/11/2/62
This should be basis for any Muslim worship in the UK in my opinion. Denouncing sexism in Islam when it contradicts their own religion is best practice. There is no reason to not point out racist Muslims either which is also contradictory to their own teachings.
Most so called "Muslims" today are unislamic in their sexism. Not calling out Muslims for unislamic sexism and putting sexist customs above their actual religion does no-one any favours. I am not telling Muslims to treat the sexes identically. I am just expecting them to manage to hold to the same standards they managed in 600 AD or they did in Victorian Britain. I hold the same opinion about sexist nonsense in Christianity when it is clear that early Christians let women be priests. The Catholic Church is a sexist institution and so are virtually all mosques in the UK. Obviously they are free to continue to be sexist in their religion and I am free to call them out for it. The Goddesses will sort them out and punish them either here or in after/future lives anyway.
This us exactly why Khan is particularly messy. Chances are his mosque has a separate section for men and women, and will contain many women wearing special dress yet his position supporting the TQ+ implies that nonbinary/ genderfluid people are a thing as well as "trans" types. Where do they go? What do they wear? As some one pointed out yes in some Muslim countries like Iran being trans is seen as a cure for being gay and people are forced to do it. However these countries don't believe in the Q+. Your options are having hormones/surgery or you are potentially executed for being gay.
It is clear Khan does not believe this. He did champion gay marriage for a start. He has spoken out against full face veils. I think he is a Muslim liberal, which is a very difficult thing to manage and often drifts into hypocrisy. If he attended one of the few ultraliberal Muslim prayer spaces we would hear about it. Most Muslims who attend mosques end up tolerating bad practices implicitly because physically their spaces treat women badly. I think it is utterly absurd to say you are Muslim and say there are not two sexes when everything in your contemporary religion says they exist and there is increasing pressure for women to wear special head coverings. The way he has acted over this debate is awful.
Contrast to Anas Sarwar the Muslim leader of Scottish Labour who also has been terrible and still refuses to admit fully he screwed it up in the votes in Holyrood which denied women exist and are equal. Sarwar however has actually switched positions ungraciously in the face of women winning their rights back and is now saying women are real. When women in his own family were wearing head coverings all the time!
Khan still can't even manage even that. As I said earlier what he is going to do at Pride in 2026 is going to be interesting to see especially when his administration as Mayor will soon be having to enforce the law saying women are real.