"You study in Rome."
In Romae studes works better? It is not clear that it is the plural form, so I naturally assumed "tu" instead of "vos". I've had this issue on other questions as well.
It should accept "Tu studes Romae". "Romae" is in locative case, It was used in Classiclal Latin (?), also there isn't a diference between singular "you" and plural "you". How can I now which "you" is?
The 'you' is ambiguous, in English it can mean either the second-person-singular or the second-person-plural, and because of that Duolingo should accept both 'studes' and 'studetis' as answers.
I thought the sentence was wrong because Romae is the Gen Sg and Dat Sg of Roma, but you have to use the Abl Sg. "in Roma" here. But "Romae" can also be the locative of "Roma", so the translation ist correct.