Dublin County council, as an example, state the car must be charging and display a valid ticket if required. Had you plugged in your car to the non-working station, you'd probably have got away with it.
In fairness to the Council, if there was a fault with the machine, having a car in the spot may impact on the ability of someone to come out and repair it.
The idea is also to get EVs to leave the spot after they are finished charging. To free up the charger rather than provide free parking for EVs.
Because BEVs and Phevs are notorious for blocking chargers the same as ICEs cars. It's more obnoxious because they know exactly what they are doing.
Someone posted on faceache about a no hybrid signs on charger (in Italy I think). Something to consider.
Just like 24 HR bus lanes eventually they'll be forced to zero tolerance on parking in charging spots. Regardless if active. It's about changing habits. Parking on cycle lanes etc. This is due the sheer volume of obnoxious parking going on.
But that will require charging spots with legal signage. Much like blue badge parking. Though many of these are private land so the owner can set whatever rules they want.