"We are eating because we are hungry."
Translation:Jíme, protože máme hlad.
This one told me I had the wrong answer when I wrote the exact same thing as the translation above except I didn't put the coma.
Yes, it may be a reason, another excepted version is " Jíme, protože jsme hladoví (hladové)
Check your answer again. DL usually ignores punctuation, so it is unlikely it cares whether you had a comma or not.