Lesson content update today

The content in the lessons just updated for me today. It still has the lessons marked as complete for me, since the content updated, I never learned it. For example, the zoo lesson added words like "rabbit" that weren't in the lessons I completed. But, they're still marked as complete for me and they're using these words in the current lessons I'm on. I tried going back and doing lessons over, but even in the previous unit there are words and grammar I never learned. I don't know where to even start now.