Hi @RP ,
Pleas follow the following steps to troubleshooting this issue:
1.Navigate to Central Administration > Manage service applications > Usage and Health Data Collection Service Application and check if the service application is up and running. Make sure you have the events checked under Event Selection.
2.Delete and then rebuild the mentioned service applications if necessary. Usage and Health Data Collection Service Application is enabled via Monitoring > Configure usage and health data collection > check “Enable usage data collection”.
3.Run this commands below:
$instance = Get-SPUsageService
$instance.Provision()
$instance.Update()
For Reference: SharePoint 2019 Empty Usage and Health Data Report
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