Unable to set NVMe or SATA mode to RAID on a PE R730xd2

Have just purchased to R730xd2 servers with both spinning disks and two lots of 2 NVMe disks.  I understand that to configure the NVMe disks I need to use dcismcfg.exe at the command prompt, and to be able to use this I need to:

Set BIOS mode to UEFI - Done

Set SATA mode to RAID - Only have AHCI Mode and Off available

Set NVMe Mode to RAID - This is greyed out and shows only as Non RAID

Has anyone else encountered this?  I'm starting to wonder if there is an underlying configuration issue, but could be wrong.