When I restart/activate/upgrade the On-Premise Poller, why is it not showing data immediately

When I restart/activate/upgrade the On-Premise Poller, why is it not showing data immediately

The following may be one of the following reasons for data not showing up after restarting/activating/upgrading the On-Premise Poller:
  1. In cases where there is a large number of monitors pointed to the On-Premise Poller, data collection for all these monitors will consume a considerable amount of time. This is because only 40 Kb of data is sent to the Site24x7 server every 5 minutes. Thus, data posting for a large number of monitors will take some time for the data to show up on the dashboard
  2. Another possible reason may be a communication failure between the Site24x7 server and the On-Premise Poller. In such cases, the data will be stored in the local server and when the Poller is restarted, a considerable amount of time will be consumed for sending all the stored data.
    Refer here for troubleshooting steps if there is a communication failure between the Site24x7 server and the setup On-Premise Poller
The threshold for sending and receiving the On-Premise Poller data is 5 minutes. So, the user is requested to wait for a maximum of 5 minutes to view the data on the dashboard