"Estamos abajo, en el café."

I've never heard of a coffee bar. Maybe it's a regional thing. If so, DL is apparently not aware of it.

In the real world, "We are down in the café" would only be acceptable in context that removes any ambiguity.
For example:
⦁ "Phone upstairs to the apartment. Tell your mother we are down in the café."
⦁ "Last month's accounts show the hotel takings are average but we are down (en baja ) in the café."
⦁ "The WiFi is up again in the hotel, but we are still down (caido ) in the café."
⦁ Two wounded soldiers are radioing for help. "We are down in the café. Get that sniper so the ambulance can come in."

Also note that, although DL usually ignores punctuation, that comma is vital. "We are dowstairs in the café." and "We are downstairs, in the café." have different meanings.