When a Software Delivery is used to force Windows Updates by running "wuauclt.exe /detectnow" nothing happens but works fine using psexec.
Software Delivery jobs run under LocalSystem account in a non-logged on session.
But, can be different causes for the lack of action after run the command as mentioned in https://social.technet.microsoft.com/Forums/windows/en-US/3a135ae3-3e69-4086-802e-2a7b59460b16/wuauclt-and-other-questions-about-wsus?forum=winserverwsus
CA Client Automation - all versions
Windows versions up to Windows 8.1 as Windows 10, Windows 2016 and newer use "UsoClient.exe startscan" as mentioned in https://blogs.technet.microsoft.com/yongrhee/2017/11/09/wuauclt-detectnow-in-windows-10-and-windows-server-2016/
/resetauthorization has been used and worked fine.
The following syntax must be used and with the same parameter order: wuauclt /resetauthorization /detectnow