Currently for Debian-based systems, Linux Package Upgrade Schedules can only detect security updates from sources listed in the /etc/apt/sources.list file.

If you have sources under the /etc/apt/sources.list.d/ directory, these are not considered by the SMA despite working correctly when running 'apt-get update' manually on the devices.

This might not be desirable for organisations that maintain their primary or additional sources under /etc/apt/sources.list.d/