Is your PC connected to the Arris NVG589 via a cable or via WiFi?
If it is connected via WiFi, your router may be flooding the other wireless devices with multicast traffic from the Editor. Now, the Editor sends only very small amounts of data, so my guess is that the device is not handling multicast traffic correctly.
For testing purposes, can you try to connect your PC via an Ethernet cable to the router and disable WiFi on the PC?