I think this might be something driver-related. On Windows 7 the 6000p uses the Windows NVMe driver, while other Intel NVMe drives (the 7600p for instance) use the intel driver.
Someone on the win-raid forum has modified the intel driver to also include the 6000p. It is self-signed, so with a few imported certificates it can work. I have not tested this, because I'm using Windows 7.