PENDING 21H2 Server consistently not installing updates during automatic patch window.

[Voyager]

Hi, were are having a 21H2 Server consistently not installing updates during automatic patch window, and as of the latest patch cycle more 21H2 servers are not installing during their auto window. The required updates are present in Software Center with "Past due - will be installed' status message.

KB's for this cycle:

KB5032336 2023-11 CU .NET 3.5

KB5032198 2023-11 CU Update

Logs we are looking at:

WUAHAndler.log
nothing in yellow or red.

-------------------------------------------------

UpdatesDeployment.log
GetUpdateInfo - failed to get targeted update, error = 0x87d00215 - this comes quite often in red.

------------------------------------------------

CertEnrollAgent.log
Registry key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Policies\PassportForWork does not exist. Error code 0x80070002 - in yellow
-----------------------------------------------------
What are we missing here? Any help will be appreciated.