Excepted student is able to continue in quiz after due date

The test was created at 9:35, but the available time is 9:30, the due date is 9:40. Late is not allowed, and auto-submit is checked. The late allowed time displayed in settings is 9:35, but not enabled.

An exception is set with the due date at 9:45. Late is not allowed.

Excepted student was in quiz until exception due date arrived, then clicked Save, Next, Previous several times before actually submitting the quiz. Student was allowed to submit the quiz (and should not have been able to since the due date/time had passed).

Ran auto-submit at 9:46, excepted student shows as Late in Total Scores, with a submission time of 9:45:52 (SAM-3113)

Did another test where I left the test open for a couple of minutes after the due date for the excepted student, and even then the student could submit even though the due date/time had passed.

Also tested this with auto-submit disabled and the results are the same. The excepted student can stay in the quiz past the excepted due date.