Ok, I see where the confusion is coming from!
I apologize, I was under the impression that you're getting a different value in meters, hence the discussion.
I see it now; the problem is indeed in conversion from square meters to square kilometers, which in my case lacked 3 zeros!
That's my bad, sorry!
So to reiterate: we have the correct value of the land area in the app, but the new server-side formula was indeed sending value in a wrong unit; this has been fixed just now.