Also worth considering that LGB has been part of PSHE teaching for decades and while it's not perfect, the UK has been a country with a free and thriving LGB population alongside a thriving Muslim population for decades. There wasn't a problem. Until very recently. The problem has arisen - as many problems have arisen - through the shoving of the aggressive (lgb)T political lobby on a very specific and very contentious agenda with no respect for anyone else's culture, needs, values, beliefs.
Yes, this is what's gone on I think. Yes, the trans stuff is anti-scientific, it is ideological. But the LBG is also increasingly presenting an ideological position, not just talking about different things people might encounter, or laws, or getting along with other people whatever views they may have that differ from your own.
It seems like because what people on the left who are nonetheless GC are calling homophobia is something they disagree with, it's ok for schools to teach ideology about the LBG, but not ok to teach gender ideology which they disagree with. The problem is lack of respect for real diversity of views. (Which I would suggest can't be neatly summed up in terms of you are homophobic if you don't support the current progressive view on LGB any more than you can say that about racism or gender ideology or really anything else.)