Book pages not showing after WP theme update

My wordpress theme Dicot was retired and so I have tried choosing other WP themes. My individual book table pages no longer show up, only the main books page. I have tried resetting each book page to Draft, then republishing, but to no avail. I tried building a new book page, but that didn’t show up either. Is this an issue with all WP themes, and do I have to reinstall and rebuild my entire bookstore?? Not sure this is worth it!

The page I need help with: [log in to see the link]