When you go under firewall and My network Zones there are 3 options, (Add, Remove and Edit). may I suggest a fourth option called Search that would search for a network.
Comodo never seems to find/detect my network when i install. In order to get comodo to detect my network I have to unplug my modem and then plug it back in while in windows.
BTW: 3.9 is excellent. I look forward to 4.0. ;D Good job Dev’s :-TU