And what we need to cover doesn't fit neatly in this small text box.
I'd fix your internet access so it's more of a classic system. Internet to some modem, router and your network.
I have a local network connecting my children's laptops to my PC. In addition I use my phone to wirelessly tether for internet. While my computer (or theirs) are connected to both the LAN (ethernet) and the phone (WiFi), I do not have internet access. If I disable the ethernet adapter (or just disconnect), I get internet back.
Similarly, my homegroup breaks when I have both the LAN and WiFi connected. Other computers in the homegroup don't show up in the homegroup list. If I disable my wireless adapter (or just disconnect) I get the other computers back.
I don't know enough about networking to know how to research this topic, so I apologize in advance if this is a common question. Thanks for any help you can provide.