If you see a red error banner that contains one of the following:
“Audit Log Enablement: Cmdlet needs proxy. Current Server FQDN :..."
"WindowsDefenderATP: Application <> doesnt exist in customer tenant <> - Audit Log Enablement: Cmdlet needs proxy. Current Server FQDN : <>.prod.outlook.com, Required Server FQDN : <>.prod.outlook.com"
First, please make sure you have audit logging enabled for all tenants.
Then, please try running any search in your Compliance Audit Portal for any tenants with this error. We have seen that doing so completes Defender's Migration and allows data to start flowing within a few hours.
If data does not start flowing within 24 hours then please delete the entire integration and recreate it. After doing so please wait 24 hours. If you are still having issues please reach out to support to get further assistance.