Drive Encryption is not supported on platforms using Intel Optane Memory-enabled volumes. This is a corollary to the support stance from Intel, regarding software-based whole disk encryption in such a configuration, as described in the Intel Support Document.

According to the above article, currently all software-based whole disk encryption solutions (such as DE) are unsupported, except for BitLocker. Use of other software-based whole disk encryption solutions with Intel Optane Memory can lead to information disclosure.

• Disable all Intel Optane Memory-enabled volumes. For details, see the How to Disable System Acceleration with Intel Optane Memory webpage.
  Or
• Decrypt, and uninstall DE, then follow the recommendations on the Intel Optane memory module update webpage.

• DE has never officially supported Intel Optane Memory-enabled volumes.
• This support statement merely clarifies our stance that hasn’t been publicly documented, but has been previously communicated to inquiring customers.
• If support for such a configuration is needed, submit a new Product Idea.
  
  To submit a new product idea, go to the Enterprise Customer Product Ideas page.
  
  Click Sign In and enter your ServicePortal User ID and password. If you do not yet have a ServicePortal or Community account, click Register to register for a new account on either website.
  
  For more information about product ideas, see KB60021 - How to submit a Product Idea.
  
  NOTE: The Ideas forum replaces the previous Product Enhancement Request system.