It's likely to be an issue with the built-in network driver that NetWorx uses to filter out local traffic.
If you are using the latest version and you had chosen the WFP driver, try reinstalling NetWorx at which time choose the TDI driver to install and reboot.
If still no joy and you need to exclude local traffic, it's possible to use a third party driver:
- Backup your usage and uninstall NetWorx.
- Download and install WinPCap.
- Install latest NetWorx again leaving the "LAN Traffic Filtering Driver" option unticked.
- When NetWorx starts, you should be able to choose one of your adapters prefixed with "Ignore LAN Traffic" from the drop-down list in the NetWorx settings.
In this case NetWorx will be using the WinPCap driver, rather its own custom driver and you shouldn't have any connectivity issues again.