The LanGuard console shows that desktops are up to date on Windows updates, but when you check the physical machine, it shows that the computer hasn't received updates for a long time.
Such a situation occurs when LanGuard is not receiving the latest updates.
The most common root cause is running an outdated LanGuard version. If you are not using the latest product version - Upgrade the GFI LanGuard.
If you are already on a most recent build, environmental changes may be preventing LanGuard from reaching GFI update servers. Follow the Updating LanGuard Server Manually When Product Does Not Get Latest Definitions or Agents Do Not Update article to solve this.
Run a scan on a machine that wasn't updating and verify that new vulnerabilities are found. If the issue persists, contact GFI LanGuard Support.