Eventhough Latin has no fixed word order, the classical word order SOV should be accepted... and especially not mixed in a sentence because its confusing for learners E.g.:
Ego Stephanus non est Corinna puella non est, sed femina est.
The "correct solutions" are "Ego non est Stephanus" and "Corinna non est puella, sed femina est"
As mentioned in the post linked elsewhere in the comments, we have been adding more sentence structures to the acceptable translations for all the sentences, but it takes a bit of time for the updates to show up on the user side. :D
Translation of "a bit of time": as much as two weeks, sometimes even longer.
As slogger said, the best thing to do is report them (using the button in the lesson, not in the sentence discussions).