VMware Identity Manager 3.3.x
The issue occurs when the Directory search attribute for the vIDM Directory is set to UserPrincipalName. This causes the domain name to be appended twice. The UI login is not affected but the API logins will fail as they are processed differently.
This issue is resolved in VMware NSX 4.1.2, available at Broadcom downloads.
If you are having difficulty finding and downloading software, please review the Download Broadcom products and software KB.
To workaround the issue select SamAccountName as the directory search attribute when creating the directory in vIDM.
Also see VMware NSX 4.1.2 release notes.