NSX Manager and NSX Edge will fail to boot if the boot options are changed from BIOS (legacy) mode to EFI mode
You see messages similar to the following when attempting to boot the NSX appliance VM:
Attempting to start up from:
-> EFI Virtual disk (0.0)... No Media.
-> EFI Virtual disk (1.0)... No Media.
-> EFI Network...
NSX manager and NSX edge APPLIANCE
NSX Manager and edge appliances come with a pre-installed operating system configured with BIOS (legacy) boot settings
UEFI mode is supported exclusively for bare metal edge deployments (via ISO image), allowing users to select between legacy BIOS and UEFI options
This is an expected behavior.