Could the BIOS update have changed one of the settings related to the drive controller? Like changed the SATA port from UEFI to Legacy, or if M.2, if this shares PCI-e lanes with PCI-e slots, may have switched back to PCI-e slot.
Which Unify, there are several with different chipsets for different CPUs?
What is you boot drive, SATA, M.2 etc?
Which socket is it connected to?