Command line SILENT version stopped working

Years ago I set up our project to be able to run in silent mode - eg Setup.exe /SC:[path to]\Silent.ini
When I run this from an ADMIN prompt now, it correctly pulls the variables from the ini file, but brings up a UX. Does this still work on Windows 11? Where should I look for inadvertent changes that can break this. I looked through the Startup actions and nothing has really changed.

Thanks,
-- Harald