When grading assignments, we've run into an issue that causes it to silently stop working and begin losing data. On the assignment grading screen, a user clicks "Update" for a specific student, assigns a grade, provides some feedback and then clicks either "Save changes" or "Save and show next" to continue. However, under certain conditions the data they enter doesn't appear on the main screen for the assignment. I've been able to replicate it when the feedback text is wrapped in a paragraph tag and the user puts a hard return at the end of the feedback. The resultant HTML looks something like this:
It appears that this problem only occurs when quick formatting is enabled, which causes me to speculate that the problem occurs when the editable comments field is being updated. When this occurs, it causes some other feedback entries to fail, even when they aren't formatted like this. Apparently something gets stuck as even going back to the problematic assignment and removing the last line of HTML doesn't always cause it to start working again.
This is causing our instructors to lose data when they are moving through assignments with "Save and show next" and don't notice that the assignments aren't being updated in the background.