I've noticed in the last few days that sometimes the feedback for the writing section shows an entry as correct, when in fact there is an error. I'm working on section 5 Level 1, and it has happened several times. The problem seems to occur when there is just one small error.
Example:
5.2 altretantto spelled incorrectly as altratantto, feedback was the corrected spelling, but did not pick up the error. However, when I made two mistakes, misspelling both altretantto and misspelling sembra as sembre, the system picked it both errors correctly.
I have several other examples from multiple lessons in this section. I have not looked at other sections.