1. Start a timed quiz in Chrome/Safari for Mac or Chrome for Win. This problem doesn't occur in Firefox.
2. Read quiz/use some of the quiz time without providing input.
3. Activate (accidentally) the back button feature of the touch pad on your laptop or press the back button. You will not see the "Are you sure you want to leave this page?" warning because you haven't entered anything into the quiz yet*.
4. Press forward button to return to the quiz(or swipe forward)
5. The timer will show that you have all or almost all of the time remaining on the quiz, rather than the amount of time that passed during your first viewing of the quiz.
6. Input answers, wait longer than the original timer of the quiz would have allowed, press submit.
7. During review you will see that all of the answers you typed were discarded and your quiz was marked as overdue. This is occurring when the "When time expires" setting is set to: "open attempts are submitted automatically"

*If you input something and select that you would like to leave this page it seems as though the Attempt/Reattempt quiz button that will appear will return to you to your in progress attempt even if it doesn't show the continue attempt button.

If after step 3, instead of pressing/swiping forward in the browser, you click the re-attempt quiz/attempt quiz button that will be visible (it won't show the button to continue an in progress attempt), it does return you to your attempt with the proper timing. This workaround is not impacted by the "enforced delay between 1st and 2nd attempts" setting.