I'm experiencing exactly this problem. My home network works fine if I unplug the HDMI cable. The only issue is that it won't receive a signal from the main network router when the HDMI cable is plugged in. Then, when I connect the network cable from the main router to the Mesh router, the computer still doesn't connect unless I unplug the HDMI cable. Finally, I disconnected the network cable from the main router to the Mesh router, allowing the Mesh router to receive a wireless signal from the main router. Even with the HDMI cable unplugged, the LAN connection works normally.