Workaround to update whether students have viewed the feedback
Click on Turn editing on from the top right.
Select Edit settings from the Edit drop-down list next to the submission.
Click Refresh all Grades from Turnitin from the top right.
Click on Turn editing on from the top right.
Select Edit settings from the Edit drop-down list next to the submission.
Click Refresh all Grades from Turnitin from the top right.