Hey Cochrane,

Hmm, there must be something within the network that is causing this communication issue. As mentioned, the PC and the gateway speak using UDP and hence they need to be on the same subnet.
Troubleshooting - This is hard as we don't know if there are any settings that you have changed within the routers (sometimes the default settings can cause blockages too). BTW - I have the same setup, using TELUS provided equipment, but only one network (your network #1) and everything works fine without any network changes at all. I wonder if there is something on the setup of the other network that is causing this
Can you try the following:

- Can you confirm that you see a solid Amber light on the gateway when it is connected to the network (Either ethernet or WIFI). This light indicates that you have a network connection.

- is it possible to take down 'Network 2' for the purposes of testing. If you can take network 2 offline and then try to connect to the gateway using your PC and the gateway on network #1. If this works, you should see the gateway show up in the device menu as a device that you can connect to. If this works (and it should as this would be the same setup I have), then it would suggest that there is an issue with the other network that is hampering the communication between the gateway and your PC for some reason.

Gateway versions:
You can see the Host processor version (LPLAN Version) using mcOTA however, you cannot see the application processor version (GWVersion) until you can see the gateway within the device menu in mcStudio. Note - the below picture shows where you would see the GWVersion and the picture is out of date. You should be at GWVersion 0.6-367 and LpLanVersion 0.8-421 

Let us know about the above
Thanks