I understand that people want various translations though I think it's good to have the literal translation even if we got it wrong then we actually learn something! (even though you would not necessary say it that way in English or another language perhaps) but it really helps to understand about declensions as much as understanding the syntax (sometimes). thanks!
I agree with your point here. However, I can also empathize with people who get frustrated when DL switches back and forth between literal translations and more conventional usages. I think some of this is unavoidable in the software, just the consequence of the virtual medium. But, in another question in this same unit, the translation did not accept "have pain" in favor of "hurts" for "болит/болят," and here it is the opposite. Not that one should expect perfection here, but I also understand why many people get frustrated with the inconsistency.
This sentence is different from У меня болит живот - there, живот = "stomach" is the subject of the sentence, and it is the thing that hurts. Or have I got that wrong?
In the current exercise, the actual subject is omitted - it's "something" in the chest, but we don't know what.
If you go by meaning, I'd think it would be acceptable, but if you are trying to preserve the grammatical structure (as far as is reasonable) probably not.
"Chest" is not the subject. For a translation in a language course it makes sense to try to keep the preposition.
Of course, "pain" is not in the original as a subject either, but it is a reasonable interpretation of the implied subject.
(See Edward Marr's comment in reply to Simon Kinsella's query.)