The words "that are" are completely unnecessary in the English translation.
I skipped them and it accepted it. I suspect the default answer has them to help remind of the correct construction when going English->French.
"The ones in the dishwasher are dirty." not accepted 27/7/20. But this is the most obvious English translation.
You might be a more advanced French speaker, but us beginners need a more direct translation as we go back and forth between the two languages.