So I looked on the wiki and it's interesting how Unsullied conjugates (at least in my opinion).
Nominative: Dovaogēdy (singular), Dovaogēdi (plural)
Accusative: Dovaogēdi (singular), Dovaogēdī (plural)
So Dovaogēdi is both the nominative plural, and the accusative singular :)
Found it by looking for Unsullied here: https://wiki.dothraki.org/High_Valyrian_Vocabulary#D
Maybe it thought you meant one member of the Unsullied, or maybe the word "the" is mandatory.
Because the word is "Dovaogedi" which is singular accusative.
So the English should be like "loves the Unsullied" (as in the one unsullied which we are definitely referring to) or "loves an Unsullied" (as in, loves a specific but unspecified Unsullied).