Apartment entrance door gap is 14mm too large

Thank you very much for the tips, I have noticed something else. My contract states a solid core door with RC2. Does an RC2 door also have to have multiple locking points? Mine has only one lock. RC2 means: "Such components prevent breaking open with simple levering tools such as screwdrivers, pliers, or wedges for a duration of at least three minutes." I cannot find anything about how many locking points must be present to ensure RC2.

I can't find anything about how many locking points must be present to ensure RC2.

Yes, indirectly you can, you yourself write:

RC2 means: "Such components prevent breaking open with simple lever tools like screwdriver, pliers or wedges for a duration of at least three minutes."

and that means: there are enough locking points exactly when it takes at least three minutes. Depending on the material and construction, the absolute number can vary.

Mine has only one lock.

Just one locking cylinder in only one lock says nothing about the type and number of bolts. There can certainly be several bolts operated besides the latch by the locking nose.

I only hope that the door has not been paid for yet. My experience has shown that if it has already been paid for, defect reports are handled unsatisfactorily, i.e. with your door they will put a strip underneath it to which the rubber strip is attached. Fingers crossed for you and I hope you get a new door.

Regards, Laura