If the AI has marked something wrongly and tightening the mark scheme does not fix it, report it to us so we can look at it.
Check the marking first
Open the student's answer. Under the feedback there is a Marking breakdown listing every criterion, whether it was awarded, and the phrase in the answer that earned it. Above it, AI reasoning expands to show how the marker reached the score overall.
Between the two it is usually clear whether the answer was misread or the mark scheme needs work. If it is the scheme, see How to update mark schemes and remark submissions.
Reporting it
If the marking is genuinely wrong, click Report Incorrect Marking on the answer, say what the mark should have been and why, and submit it.
When no mark came back at all
Occasionally a long answer returns without a mark, usually because something in an attachment could not be read. You are not stuck: fill in the mark and feedback yourself and it counts as marked from then on.
What students see
Students see their marks and their feedback. They never see the criteria, the quotes or the reasoning.