Store the report as primary. You need to be logged in as a developer at the same time to be able to do so.
I want to add report total in interactive grid in the main report/ Primary report.
Actions button> report> save.
1. Log in as developer
2. Run the app
3. Open the primary report.
2. Reset the primary report (this is only needed if you did any changes in that session already).
3. Make changes to the report like adding an aggregate.
4. Save the report as default primary report.