Total shot in the dark but because it's bad English...."from" can be further translated to "since" and it make a lot more sense to say the phrase as they have it.
It would be correct if, say, it was June and we were talking about the future. 'We live here since July' is also bad English; it would be marked incorrect in a TEFL class.
No, it's just that the Italian uses the present because the speakers are still living there, while English uses the past because the action started in July: it wouldn't be correct to say "We live here since July".
I agree it wouldn't be correct to say "we live here since July" but that was given as a correct answer by DL
american english: "we have lived here since..." or "we've been living here since....."
I gritted my teeth and put 'We live here since July', which was accepted but is terrible English. Sometimes it is difficult to second guess DL' s answer and using the past tense was risky. If in doubt be literal.