Sounds to me like several things may be being confused:
Fire exit door - a means to escape the building when there is a fire. Needs appropriate signage, lighting and door handles to help people exit in a hurry. I would have thought the rules don't care if the door is open or not when there is no fire.
Fire door - a door that needs to resist the spread of fire. Often between fire compartments in a building. These need to be closed when there is a fire to do their job. Various ways are used if making sure they are closed in a fire are used like signs saying "keep shut", springs that close the doors, automatic closing doors etc
It sounds to me like the problem may be that it is a fire door and that the way they are ensuring it is closed in a fire is by keeping it locked shut. Are there springs/door closers on the door so that it closes automatically when you do open it?