Hi @Graham Miranda DRK ,
In addition to the links shared by Troy, as regards to the error code 80070643 in the last screenshot and the second log file which is related to the ServiceControl.ps1, I found the following links that hopefully can be helpful:
Exchange 2019 CU2 KB4509408 - Error 0x80070643
Exchange Server Security Update KB4540123 fails with 0x80070643
Please Note: Since the second web site is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.
You may make a backup of the ServiceContol.ps1, then modify it with reference to the links above and see if it works.
Beside, the first error log file shows an error with the database "ITDBM1-21012019" cannot be mounted. As per this error, you can try renaming its database folder and then retry the update.
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