Install at idle option

I am trying to get the Zoom client installed/updated on our fleet of Windows 10 machines and using the below command.  Using the 64bit version of 5.14.0 (13888)

msiexec.exe /i ZoomInstallerFull.msi /qn /norestart zConfig="AU2_InstallAtIdleTime=Enabled;ForceSSOUrl=OurZoomURL;AU2_EnableAutoUpdate=Enabled;AU2_SetUpdateChannel=0;AutoSSOLogin=1"

The install is working to install or update an older version of Zoom, but the AU2_InstallAtIdleTime switch doesn't seem to be working as in testing instead of waiting for the meeting to be finished it closes the zoom session I have active to perform the install.

Is there anything obvious that I am missing or doing wrong?