I have tried F6C, but with no luck.My config:MB: X570 ProCPU: 3900XRAM: 2x G.SKILL Trident Z RGB Neo 16GB Kit 3600 MHz CL14 (F4-3600C14D-16GTZN)Primary SSD: Intel Optane 900P 280 GB, U.2 with M.2 adapter plugged to M2A_SOCKET (SSDPE21D280GASM)OS: Windows 10 Pro 1903 with all updates and AMD chipset drivers 1.9.27.1033, fast startup disabledNon-OS SSD: Samsung 970 Pro 1 TB M.2 plugged to M2B_SOCKETSATA SSD: WD Blue 2 TB (WDS200T2B0A)SATA HDD: HGST Deskstar NAS 10 TBSATA Optical: some random LG burner HL-DT-ST BD-RE GGW-H20LMy original BIOS is F4 that works kind of normal (more to that later).When I flash to F6C then immediately after the reboots I can see Intel Optane as boot device in BIOS:It is also listed in the devices with all details:The only change I make in BIOS is to disable onboard audio (not to interfere with my USB card). Everything else is default, no XMP, no overclocking.First boot to Windows is fine, however as soon as I reboot again, boot device is gone and the boot will fail with error "Reboot and select proper boot device or insert boot media in selected boot device and press a key."When i enter BIOS Intel Optane is no longer listed as boot device:However it is still visible in device details:Power cycling, restarting, loading defaults - nothing helps. It will not boot.When I flash the BIOS back to F4, it behaves in similar way (Optane is visible before first boot, after reboot from Windows it disappears), but with the difference that the system boots normally even if Optane is not listed in boot devices.It is a pity since I was looking forward to ABBA. I hope that they can fix it soon...