I have 3 SSD. A Samsung EVO 480, EVO 860 and EVO 870, All connected per SATA cable. This problem only affects the 860 and 870 which are V-Nand.
The 870 was brand new and instantly had the same problem as the 860 already was having.
Sometimes when I start my PC (this can be from standby, full shutdown or crash) those 2 drives (or only 1 of them) completely disappear, so not showing up in bios or anywhere.
I can bring them back while windows is booted by just unplugging both power and sata cable and reconnecting. (power first)
What i did:
Tried to mess with windows power settings
Sent one of the drives to samsung support. They reinstalled the firmware and sent it back but problem persists unchanged.
Changed cables and slots.
Tried to enable Rapid mode but OS doesn't boot anymore that way
Updated chipset drivers and some others (SSD firmware already up to date)
Run some tests with Samsung Magician software, everything seems good as long as they are detected
Since it also happens after a crash, im assuming it has nothing to do with windows
There has to be something different about the EVO 840, since it never had that problem. This might be key
MSI x470 gaming pro
Ryzen 7 2700X
Radeon RX Vega 56
be quiet, Straight Power 11 850W
Some PCI usb controller
2 internal HDD, 1 external