Why custom script from a report is not working when I add this report as "Merged Report"
Custom scripts are currently not supported for Merge Report functionality. For example, if you use "Merge Report" in a mailing or a message template, the custom script from the report used will not work.
If you wish this functionality to be added in the future version of Oracle Service Cloud please submit an Enhancement Request.
More information on Answer ID 966: Submitting an Enhancement Request