"Aren't we talking about two different things here?"
Translation:Reden wir hier nicht über zwei verschiedene Sachen?
"Anders" means different from something or refers to something else, e.g. "Das ist etwas ganz Anderes." could be translated to "That is something else entirely."
"Verschieden" on the other hand is relative and used when multiple things have differences between them, like in this duolingo sentence. In particular it is normally never used with singular objects, unless you use it in the form "Objekt eins ist verschieden von Objekt zwei."
In many cases both can be translated as "different" and sometimes you could express the same meaning using either word, although you might have to modify the sentence structure to make it work.
That sounds like the German equivalent to "Are we talking about two different things not here?", i.e. the "nicht" or "not" would modify the word "hier"/"here" and not the verb of the sentence. It also sounds rather awkward in both languages.
The translation given by duolingo is entirely fine, as are the ones suggested by "Biomax" and "karenskywalker" in their comments.