by Ken Task.
Run 'hidden' /admin/tool/health/ as admin level user via web browser.
Will check questionbank and present a screen showing issues it found as well as a button for 'suggested solutions' ... which are usually SQL queries to run from mysql client or phpmyadmin on the DB of the site having issues.
If suggestion to fix not presented at least you might have some more info to share back here.
'SoS', Ken