Why are quiz attempts marked late even though there is an Until Date/Time and Due Date established?

cvera1
Community Participant

Today an instructor informed us that some of her student submissions for a quiz were being marked late even though she has established an until date and a due date that are the same (match e.g. March 1 at 11:50am) The quiz is also timed at 20 minutes and it allows for unlimited attempts. There are also multiple dates established and this student fell into the 11:50 due date/until date/time. One student made three attempts, two were within the 11:50 due date and until date time frame but the third and last attempt shows having submitted at 12:03pm. I wonder how this is possible since there is an until date established 11:50am so wouldn't the system have submitted this/cut student's attempt off at this time and no late marks would have been possible? Is having a timer in combination with the until date an issue? Student did start the third attempt a little later and would have not been granted the full 20 minutes if the until date/time should have auto submitted. 

In addition, we noticed that when we go to see the students submission information from the Gradebook column by clicking on the comment/bubble icon in the student's cell, the window displays all three attempts as "late" even though only one was submitted past the due date and time. In SpeedGrader the last attempt was marked late because it was technically late and the other two were not. The gradebook cell is also shaded pink.