I seem to be finding that on 2018 MacBook Pro's that when i enrol into the JSS they report that the start up disk is encrypted (i.e. the default out of box version of macOS - currently 10.13.6 - partition).
However macOS doesnt have FileVault 2 on by default and when checking on the device locally it shows not encrypted, this is causing an issue where the JSS has the wrong state and therefore wont show the policy for enabling FV2.
The only workaround ive found is to manually add the machine to a policy for FV2 individually then run a Policy/Recon to force it to pick up the changes - this then allows the process to run without issue
