How come it is "jsou" and not "je"? From what I can tell, it's connected with dveře which is singular.
Dveře is always plural the same way scissors or trousers are always plural in English. Notice that a door is also often made of two parts which you can open.
Duo accepted "our doors are always open" so I wonder whether a singular or plural translation is possible here in the absence of context?
Obviously both when it was accepted...
Dveře is always plural in Czech, both for "door" and "doors" as already stated above.