Diagnostic settings should be enabled for each EventHub to ensure events are logged and available.
Remediation
Perform the following in the Azure Console:
In the Azure portal, navigate to your Event Hubs.
Select Diagnostics settings under Monitoring in the left pane, and then select + Add diagnostic setting.
In the Category details section, select the types of diagnostic logs that you want to enable. You’ll find details about these categories later in this article.
In the Destination details section, set the archive target (destination) that you want; for example, a storage account, an event hub, or a Log Analytics workspace.
Select Save on the toolbar to save the diagnostics settings.