Symantec Encryption Desktop does not support Single Sign-on in Windows 10 or Windows 8 when Fast Startup is enabled if the machine is using BIOS rather than UEFI.
This is a known issue documented in the Release Notes for Symantec Encryption Desktop 10.3.2.
Symantec Corporation is committed to product quality and satisfied customers. This Feature Request is currently being considered by Symantec Corporation to be addressed in a forthcoming version of the product.
Technical Support filed a Feature Request to add this product feature. Note that a feature request is exactly that, a request. There is no committed date for this request from the Endpoint Encryption Product Management team, nor from the Endpoint Encryption Engineering team at this time.
Please be sure to refer back to this document periodically as any changes to the status of the request will be reflected here.