I've got an optiplex 5055, which has a PCIe SSD.

I've swapped the SSD for an Intel one and installed Windows 10 Enterprise 1809.

Ran the Dell command update and everything it running fine - except if it reboots.

If you reboot, a BIOS error (and alarm) comes up reporting no hard disk present to boot from.

However turn it off and back on and it is fine.

Using UEFI boot of course and have AHCI set for SATA (not that it should be used) and secure boot is off.

Any ideas?