This is a known issue and Defect ID 258043 was created to provide a fix in a future release:
Defect 258043 :After a full collection, the report "Access Templates linked to Managed Units" displays no data.
This issue has been identified as a product defect and logged as defect ID 258043.
Waiting for a fix in a future release of Active Roles.
Please refer to the “Resolved Issues” section of the Product Release Notes when new releases are available to identify if a fix for this defect has been implemented. Product Release Notes are available in the “Product Documentation” area of our Support Website at support.oneidentity.com