When activating the Office 365 Securlet, the following error it shown:
Securlet is not activated, because the domain name of the authorizing user does not match the primary or secondary domains configured in CloudSOC.
This error is happening before authenticating to Microsoft.
If the error is happening before any authentication to CloudSOC, the issue could be with old data stored in the CloudSOC database for previous O365 Securlet Activations.
Contact Broadcom CASB support to help get any old data cleared