A chart may appear empty or blank even when network traffic is present. This typically indicates that real-time data collection is not configured for interface protocols.
To resolve blank or empty charts
You can also click the Flow Reporting link displayed at the top of the Protocol Monitor page when data collection is disabled.
Charts must begin populating within the configured refresh interval.
The Protocol Monitor page itself does not contain configuration settings. All data collection settings are managed from Device > App Flow > Flow Reporting. The Protocol Monitor is a display-only page that renders data collected by the AppFlow engine.