I am only on level 8 but I have noticed this several times already. In the example sentences, Wanikani will be using a synonym for an item but that synonym is not listed as one of the accepted answers. I have been manually adding these synonyms as I notice them, but why wouldn’t these already be listed as acceptable synonyms to start with?
Here is an example of what I am talking about, where all of the example sentences here use “conflict”:
Because conflict is not a synonym. Translations are rarely 1 to 1, unless it’s straight up nouns. The word conflict is most likely used because it makes the most sense in that sentence. Words are used differently and have different nuances.