Save button under Enterprise/ Login Experience doesn't work - "Invalid strategy waad" error

Problem statement

We have an issue when clicking Save in an Enterprise connection. We are trying to add another Domain in the HRD section of the WAAD enterprise connection, but when clicking on save, it fails, and it does not save changes.

Symptoms

They are trying to add another Domain in the HRD section of the WAAD enterprise connection, but when clicking on save, it fails, and it does not save changes.

{
  "statusCode": 400,
  "error": "Bad Request",
  "message": "Invalid strategy waad"
}

Cause

For some reason, after a tenant migration, the tenant domain was not migrated for the WAAD connections. So as the AAD tenant domain was empty they could not save any change in the connection.

Solution

Fill in the AAD tenant domain, and click on save (in the WAAD connection).