For examples of incorrect guidance, how about The Guardian today:
Under existing law, transgender people can use the toilet that matches their gender identity ...
They do go on to say:
,,,but, in 2022,the Equality and Human Rights Commission said that, under the Equality Act, people who do not have a gender recognition certificate could be excluded from single-sex services or facilities, including toilets, if it is “a proportionate means of achieving a legitimate aim”.
But the juxtaposition of these two claims seems to imply (falsely) that the EHRC guidance is different from (and contradicts) 'existing law'.
https://www.theguardian.com/society/article/2024/may/06/how-the-single-sex-toilet-law-in-england-will-work