Were they originally single-sex toilets that have been 'rebadged' as mixed sex? If it's an old building, this is possible, and yet another example of taking a perfectly adequate AND reg-compliant toilet provision and ruining it with rebadging.
If they have removed the old toilets, and installed these new ones, since Doc T came into effect, these toilets are not legal - mixed handwashing facilities are not OK.
1) Toilet accommodation in buildings other than dwellings—
(a) must consist of—
(i) (ii) reasonable provision for male and female single-sex toilets, or where space precludes provision of single-sex toilets, universal toilets, and
(b) may consist of universal toilets in addition to single-sex toilets.
(2) In this requirement— “single-sex toilet” means toilet facilities which—
(a) are intended for the exclusive use of persons of the same sex, and
(b) provide washbasins and hand-drying facilities in—
(i) either the toilet room or cubicle, or
a separate area intended for use only by persons of that sex.
“universal toilet” means toilet facilities which— (a) are provided in a fully enclosed room which contains a water closet and washbasin and hand-drying facilities, and (b) is intended for individual use by persons of either sex.
Toilet accommodation: Approved Document T
IANAEOUKBR - 'I am not an expert on UK building regs'
so I'm not sure how much of the UK Doc T covers, though it is a 'HM Government' document - but I think it might be worth mentioning in complaints if the building is new, or if they have actually replaced the toilets with new structures - 'Can you confirm that this new configuration meets with all the requirements set out in Document T of The Building Regulations 2010 v.2024 and all other relevant regulations?
At least it puts it up to them to consider their regulatory responsibilities, which it looks like lots of venues don't. and confirm or deny that they are meeting them.