In my home village here in Ireland, I parked in a disabled zone and hadn’t noticed my disabled parking permit was displayed upside down (therefore incorrectly).
Because the warden had started writing the penalty ticket and I even after I showed her the details were valid, I was still given and 80 euro fine. I appealed but was unsuccessful. There are other markings on my car and adaptations that show very visibly that the car owner is disabled.
I find there is more leniency in the USA, I used to travel back and forward there with work and they accepted my Irish Parking permit with no issues.
We have disabled parking bays in our village main street surrounded by high kerbs. For some of them you need to take your life in your hands and travel on the main road (with cars, buses and truck) to get a low enough ramp to get onto the footpath (sidewalk). I think this problem is world wide