Ethernet - Router not assigning IP addresses to some devices.

Yes, there is one cable feeding into the router coming from the main switch. 

Every room in the house that has a wall jack feeds there. Two of the rooms also have switches to feed devices into the wall jack, which then feeds into the main switch (hub). 

I hope I am explaining that clearly. 

It is not ideal, but it's how they set me up. 

I have included a photo of the main switch (hub) which feeds to the router, as well as a picture of the router. 

Ok, thanks so much, this helps.

So the switch in the first picture is in the same room as the BGW, right? 

And the 4 black cables that go into the wall plate must feed the wall plates in the other rooms, correct?

But where do the two white cables connected to the switch go?

And that blue cable that goes into the 5Gb port on the BGW, where does that go? 

That's the one I suggested should go to one of the yellow ports because that 5Gb port sometimes does some goofy stuff to the network.

The switch is actually in the living room, upstairs from the router, which is in the basement. 

The 4 black cables feed the wall plates in the other rooms, correct. 

The two white cables: 

1 runs to the wifi extender sent by ATT

The other runs to a HomeBase for my Eufy Security Cameras. 

The blue cable that is in the 5Gb port goes up into the wall and vanishes, to then go on to connect to the outlet in the living room which the switch is. 

Alright, I'm getting there. 😁   So the blue cable eventually ends up at one of the ports in that wall plate, then into the one switch you have in the living room.  The switch then distributes the network connection back into that wall plate and those three ports connect to three other wall plates/rooms.

And you have two more switches, one each in two other rooms?

And the problem with the two computers only show up when connected to the same port or switch?

And nothing has changed in this setup since it was working just fine, right? 

Haha! ☺️ Again, I really appreciate all of your help! 

You are correct on all accounts. 

Nothing has changed in their setups, two different OS, and the only thing I did was power them both down for the evening to conserve energy. 

Good Monday to you. Are you still working on this issue? I stopped posting after tonydi started helping. He's more familiar with ATT hardware than I am.

Happy Monday! 

Yes, still working on this issue. Working on the computers wirelessly at the moment, but I’d love to get the Ethernet back. 😂

Did you swap the blue cable to the router into one of the yellow ports?

I have tried that, no luck.