Hi Mark,
Creative cloud packager creates a combined installer for Adobe CC apps however there are few apps which go to exception folder in a package and lightroom is one of them.
In order to install ligtroom, you would need to go to exception folder and user ExceptionDeployer.exe. Please go through the article below to understand the ExceptionDeployer.exe install workflow.
https://helpx.adobe.com/creative-cloud/packager/installing-products-exception-folder.html
Thanks,
Ashish