Kaseya knows which updates are required by doing a patch scan. Before troubleshooting any problems run a patch scan to ensure that it's working with the latest data.

When troubleshooting how Kaseya knows whether or not a patch is needed, check the Windows Automatic Updates website. See what that reports as missing and whether it matches what Kaseya is telling you.

When creating scripts to add/remove updates, see Hotfixes for switches, etc