When the role right "run reports at higher resolution" is assigned to the user, the dashboard will still display data using default resolution in this scenario, 1 hour  resolution still used.  All reports will use the default resolution.

DX Performance Management CA Performance Management

Edit the dashboard report and change the resolution field to 5 minutes.  Once you save the report you should now see 5 minute resolution data for last 30 days.

Additional information regarding running reports at higher resolution is available here: 

https://techdocs.broadcom.com/content/broadcom/techdocs/us/en/ca-enterprise-software/it-operations-management/performance-management/3-7/using/views/data-resolution.htmlad