This known issue is closed due to the decommissioning of Blackboard on the 31st of August, 2021
When setting up a quiz for “One at a Time” question presentation, an Instructor has the option to Prohibit Backtracking to previous questions. If help text is turned off, a visual bug impacts this setting causing it to display on top of another.
When displayed as shown above, the setting can still be configured. The round radio buttons control the toggle between “All at once” and “One at a Time”, while the square checkbox controls the “Prohibit Backtracking” setting
The display can be corrected by enabling Help Text, toggled by the ? icon near the top right of the page