Based on your scenario, it sounds like you could be using key vault for Azure Disk Encryption (ADE). If that is the case, you will need to confirm the object (secret, certificate, key) exist on the Key Vault. You must also confirm the Key Vault is enabled for ADE. Creating and configuring a key vault for Azure Disk Encryption on a Windows VM - Azure Virtual Machines | Microsoft Learn
If the object (secret, certificate, or key) no longer exist (i.e. permanently deleted) on that Key Vault, you will need to work with the Azure VM teams to review the options to recover the VM.
Please feel free to reach out to me at the address listed so that I can open the support case for you.