Has anyone worked out why this is in the N/N nouns lesson as they all seem to be M-/Mi- nouns and it gets very confusing as such?
Yes, I think I know why. The learning method here is an accumulative one. Each lesson adds on to what you learn in previous lessons. In order for you not to forget what you have learned before, DL keeps mixing things from earlier lessons into new lessons. This is actually a really good way of doing it to keep the student "on his toes".