Xfinity Pod - Ethernet cable works for desktop but not for 3 different laptops

I want to connect a laptop with dodgy wifi adapter (older computer) but with a working fine ethernet port to a pod.   When the laptop is connected via cable to the gateway everything works fine.   So, we know it's not the cable or the computer.   When I hook the laptop to a pod using an ethernet cable, I get either no cable detected, or a cable detected with no internet available. 

If I hook the same cable (with no internet) to my desktop PC, which I am typing this on using the ethernet cable connected to the pod, it works fine.   So...how can this work differently for laptops and desktops?   I've tried two different cables (both cables work when connected to the gateway; not to the pod).   The pod is literally brand-new out of the box a few hours ago and there are several wifi devices connected to the pod.   It's only the ethernet connect and only to laptops (tried 3 different laptops) that are not working.  

Did make sure that the wifi was not connected before we connected the ethernet.  

Tried:

- troubleshooting ethernet connection; nothing

- removing ethernet adapter and reinstalling; nope

- removing device from wifi devices on Xfinity app; nada.

What can I possibly be missing?

Thanks!
Chris