AFAIK, the presence of EventID 1801 on Azure Gen2 VMs indicates that the guest operating system lacks the permissions to directly modify the UEFI variables that are managed by the Azure platform infrastructure. Since Azure controls the virtual firmware and the Trusted Launch environment, it is expected for the OS to report a failure when trying to write to these protected keys. You can generally ignore this event as long as the VM continues to boot correctly and the Azure portal confirms that Trusted Launch and Secure Boot are enabled and healthy.
The discrepancy in certificate status across your servers indicates that the underlying Azure host nodes are at different stages of the rolling update for the 2023 UEFI certificates. The fact that some servers report false for the newer certificates simply means the virtual firmware for those specific instances has not yet been updated with the 2023 KEK or CA. Microsoft is managing this transition globally for Azure infrastructure, so you do not need to take manual action to push these certificates into the UEFI.
You should not manually set the registry keys under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecureBoot to force an update. In an Azure environment, forcing these updates through the registry can cause conflicts with the platform-managed secure boot process or lead to persistent error logging without actually updating the underlying firmware. Your primary responsibility is to ensure that regular Windows Updates are applied, specifically those related to the Secure Boot DBX (Forbidden Signature List), which allows the OS to recognize and trust the new certificate chain once Azure updates the virtual hardware.
If you want to verify the current status of Secure Boot on a specific VM via PowerShell, you can use the Confirm-SecureBootUEFI cmdlet to check if it is active regardless of the specific certificate versions.
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hth
Marcin