Report Editor, Home > Records is not showing custom table

Summary

Connected workspace opens for one report but not for another

Content

On a report A when you double click the record it opens a workspace for the connected custom table A which can be seen in report editor on the Home tab in Records. On report B which is the same report but a different table it doesn't open the workspace for the connected custom table B because it can't be seen in Home > Records. 

They both used to work. Two things happened at the time the report stopped working. The join was changed to an Outer Join in both reports and there was an upgrade to 20D. I have all the permissions to see table B and the whole report is showing data from table B but all I see in Home> Records are contacts and organisation and table B.