When two users that have exactly the same workgroup access, and one of them sees fewer project time entries in a Cognos time listing report, the report is likely based on the Project Time query subject.

The Project Time query subject in Cognos checks for both project access and workgroup access.

The Time Combined query subject only checks for Workgroup access. If you do not need to enforce project access, you can use the Time Combined query subject instead of the Project Time query subject.