Symptoms
SSL support checkbox should exist when we select Exclusive IP while migrating a brand according to the guide Migrating a Brand, but such checkbox is missing.
Cause
It should be possible to enable SSL support during Brand migration otherwise Brand will have SSL turned off after migration. The issue has been fixed in OA 5.5 update 9.
Resolution
Please update to OA 5.5 update 9 to fix the issue. To workaround the issue please enable SSL support manually in CCP via Web Hosting Settings for the Brand.