When moving guest machines from one Hyper-V to another, we have to export the originating shielded certificates. You can export the certificates in Certificate Manager on the origin Hyper-V and then using the following commands to import into the destination Hyper-V:
certutil -importpfx "Shielded VM Local Certificates" "E:\Shielded VM Encryption Certificate (xxx).pfx"
certutil -importpfx "Shielded VM Local Certificates" "E:\Shielded VM Signing Certificate (xxx).pfx"
For Internal Use: \Machine Notes\2023 Import Shielded Certificates