My bathroom underfloor heating is not heating or cooling, even though it’s on!
Heating/cooling up a solid concrete floor to the desired set temperature can take hours, so don't panic if it doesn't immediately heat up or cool down. It should get there eventually.
On the flip side, the advantage of this is that the effects are extremely efficient and long-lasting.
One thing you should also check is whether the underfloor heating zone is set to ‘eco-mode’ or not. If your bathroom is in eco-mode, then the zone will only be serviced during certain times of day to avoid peak electricity prices (for example in the morning or the evening).