On a post about Great Britains sex-based spaces laws that was painted as trans people being “banned” from public restrooms, I pointed out that they are not banned, they just have to use the ones that are for their sex.

Nothing incorrect there. 100% factually correct. Sex and gender are constantly spoken about as being separate things now, since sex is not changeable (despite what the person who replied thinks)
I was then permanently banned for “transphobia”:

Do they even understand what a phobia is?

The part thats transphobic in my view is not allowing trans folk use the toilet that alignw with their actual gender.
Sex != gender? Sure. I dont care tho, this is a question for medical science.
Having a fully transitioned women with tits and lip stick going into the mens toilet is just ridiculous. Alternatively, having a trans man with a beard with massive muscles in the womens toilet is equally absurd.
It is also ridiculous to have such a villainisation of non passing trans folk using the toilet of their gender. What are we gonna do, bite you?
Toilets should be seperated by gender, not sex. Segregation based on sex isnt even enforcable anyway.
Also the toilets arent made for your sex (other than urinals I suppose). An actual toilet is sex agnostic.
So yes I do think this idea is transphobic as it places stress on the day to day lives of trans people (i.e nervously asking do i pass or not before entering a toilet). As to whether you should have been banned for that, perhaps they should have been more paitent with you.