Hi Sebi,
Surface pro 4 is still not supported and Symantec Engineering team is working on it. Please refer to below mentioned articles and subscribe to it via email. If there is any update you will be notified.
Symantec Drive Encryption 10.3.2/Symantec Endpoint Encryption 11 and systems with NVMe drives.
https://support.symantec.com/en_US/article.INFO3183.html
Bug Report: Attempting to Encrypt Surface Pro 4 systems with Symantec Drive Encryption 10.3.2 MP10 or above results in BSOD and Errors
https://support.symantec.com/en_US/article.TECH233421.html