Project Online custom sharepoint site pages will not populate notebook

I have custom sharepoint pages in project online, recently the notebook on the project SharePoint Site stopped working.  When a brand new site is created, user clicks on the notebook link and it displays an error message, "Sorry, something went wrong. Item does not exist. It may have been deleted by another user".

I found a temporary workaround, in the Site Settings >Manage Site Features, I deactivate the notebook and then activate.  The notebook will then create. I also tried to deactivate / activate on the site page template but it does not resolve the issue.