HelloZephyr Vance
That boot failure is a classic issue after a host motherboard update, as the firmware flash often resets the UEFI Secure Boot certificates on the physical node and breaks the trust chain for Gen 2 VMs. Since you are seeing Secure Boot validation errors in the event log, there is absolutely no need to recreate the entire virtual machine. Just shut down the affected VM, go into its settings, and navigate to the Security tab. From there, try changing the Secure Boot template from Microsoft Windows to Microsoft UEFI Certificate Authority, or temporarily uncheck the Secure Boot option altogether to see if it boots. Once the VM is back online, you can shut it down and re-enable the standard Windows template to restore your security baseline. If this quick adjustment gets your server running again, please accept the answer to help other cluster admins facing the same issue.
Tracy Le