When you try to download Microsoft 365 App manually you get the error "Download of Office 365 file failed, error ="
Upon Checking the log file PatchDownloader.log you notice an error
Error: Authentication of File failed, error 0x800b004
Based on findings at this point in time. If you have recently installed the Oct 2020 Update (KB4577668) on the server this may be the cause of the issue. As there is a known issue due to some increased security around the download of the Office (aka Microsoft 365 apps) update files.
Current workaround is to remove the Oct 2020 Update (KB4577668) on the Primary Site Server and then restarting the Server.
Once the server restarted, rerun the task and it should complete successfully