If a student says they completed work that's showing as missing in your Scorebook, here's how to check.
1. Check Scorebook for a submission
Open the student's row in Scorebook, scroll to the assignment(s) in question, and click into each one. If there's a submission there, you'll be able to open and review it. If there's nothing to open, it's currently showing as not submitted.
Full steps: How can I use Scorebook?
2. Check Session Logs to see if they were active
If you want to confirm whether the student was actually working in the course around the time they say they submitted:
Log in to your Educator Portal.
Go to your Roster and search for the student.
Click into their account and select the Session Logs tab (located between Enrollments and Account Overview).
Filter by the relevant timeframe and course to see their active, idle, and review time for that period.
Full details: Time Tracking: Session Logs
3. Generate a Work Sample for a full record
If you need a complete export of everything a student has submitted, you can generate a Work Sample for their enrollment, choosing a custom date range or All Time.
Full steps: How to Use Subject's Work Sample Feature
A note on the To-Do List
The To-Do List (with auto-checkmarks for completed work) is only visible from the student's own account. There isn't a teacher-facing view of a student's personal To-Do List, so this isn't something you can check on your end.
One more thing to keep in mind
"Missing" can also simply mean the assignment's pacing due date has passed, even if the student completed it late. Subject has no late penalty, so late work still counts once submitted.