SecureAuth IdP Version affected: 9.0.1, 9.1, 9.2
When you have two trusted Active Directory domains, and use one service account from one domain to connect to both domains, you might experience an issue with the "Test Connection" feature in the admin portal.
The "Test Connection" button action is ignoring the "@" field, and using the domain you are connecting to as the domain prefix. This will not work if you're connecting to a domain with a service account from another trusted domain.
Provide the UserPrincipalName of the service account in the first field, and ignore the second field as seen below.