"Our passports are with me."
Translation:Unsere Pässe sind bei mir.
Should probably also be accepted; report it.
Why is bei used rather than mit in this sentence? If both would be correct, is one more common than the other?
Thank you for your help!
bei mir = at me, on me, with me, on my person, in my possession
mit mir would be "together with me" -- you could say, for example, Komm mit mir! "Come with me!" because I will be going and you will be going and we will be together during this going.
The "to be" is not really an activity that the passport can accompany you in; you wouldn't say "I am being and my passport is being and we are being together" nor "My passport is together with me".
For the same reason that "My passports are together with me" makes little sense.
mit is generally used for doing something together, not merely for being in someone's presence or possession.
Your comment is not useful unless you identify which sentence specifically you mean (nobody can see what you saw as the "correct answer"), what about it is in incorrect and why, and ideally what you think should be the correct version.
I may have missed something, but why is it not "Unsere passe sind bei mich"? Does "bei" invoke the dative?