New Ethernet Adapter not connecting

The new Ethernet Adapter --Greatangle Multiple USB-C USB 3.1 Type C to USB RJ45 Ethernet Lan Adapter -- which arrived yesterday via EBAY after many weeks, is not working. Before I enter into the return / replace / refund procedures I would like to have confirmation (or otherwise) that I have checked everything possible. I now have two adapters, the old USB 2 (Ethernet 7) and the new USB C / 3 (Ethernet 2, in the clip above). I can have them both plugged in at the same time so when I switch the old one off my service switches instantly to WiFi indicating 2 is not working for Ethernet (it also has USB sockets which do work OK). I have changed around and checked all manner of things, including the cables, the Hub sockets, the PC sockets. I have also checked W 10 OS, such as Device Manager, and Settings. No errors / failures / absences are shown. The new Adapter is reported to be "working well" (though I don't trust that to mean anything, from past experience). In Settings Ethernet 2 is shown as not connected whereas 7 is shown as connected, and the result is the same with 2 if I switch cables / cable adapters, PC and Hub sockets. I have used the Troubleshooter which reports an error, ie. a device is not connected.

So I think I have done a thorough inspection. Is there any other possible cause of the problem I have not checked?

Thanks for your reply. Although I have occasionally had both connected at the same time 99% of the time it has only been one of the Adapters connected, including the fact that by 'connected' I mean physical connection by which I mean that the cable for the working Adapter 7 is removed. So the problem cannot be a conflict.

For the record I must correct my statement that it was bought through EBAY, as it is AMAZON who are the supplier, so I will be connecting them about my next step. The Adapter was inexpensive so it will not be worthwhile returning it..

For a while I thought I had discovered the source of the problem, to do with Thunderbolt / Lightening cables / IOS and the confusion over the increasing use of USB C for Ipads etc., so I started looking for cable adapters (there are plenty). Then I realised the Ethernet Adapter is itself the USB C adapter and connects OK to the PC USB C port. So I am now no wiser. Could the Ethernet Adapter be only for IOS, Thunderbolt, not Windows? I am confused.

I have at last learned that Thunderbird and USB C are not compatible in operation ------ "you need to be careful if you have USB-C ports on your computer and the functionality they provide. Thunderbolt support requires an additional chipset on the computer’s motherboard, and most cheaper computers aren’t going to bother with the extra expense. Just because you see a USB-C port on your computer, it may not be Thunderbolt capable (it most likely isn’t – USB 3.1 protocol-based parts are far more common)."

I was mislead by what I read about this. But does it mean that USB C compatible Adapters are not available. I hope not but must check it out.

I now own 2 surplus new USB C Ethernet Adapters which are for Thunderbird. It is my own fault for not checking this out thoroughly enough --- fortunately they did not cost a lot. It seems another thing to look out for is reference to MAC, but there are suitable USB C Windows compatible Adapters so I will order one today. I learned that USB C is not now Windows specific but is increasingly being adopted for other hardware.

Although I now have the right GB ETHERNET Adapter and the right Cat 6 cable I have not yet got it working at all reliably, connection lasts a second only, then it defaults to WiFi. In Device Manager there is an error mark against the correct DRIVER which is USB GB E FAMILY CONTROLLER. I have repeatedly run the Troubleshooter and searched numerous Settings but this notification is surely the smoking gun "Windows cannot load the drivers for the device (Code 31)" The Driver is reported to be up-to-date and "the best available" (installed only weeks ago). In Properties Microsoft Network Adapter Multiplex Protocol when ticked reverts to unticked; and in Status I see the following: IPV4Con "No network access" / IPV6Con "No network access". At some locations when I click Enable, Ethernet remains Disabled.
I suspect that 'all' that is wrong is a Setting not set correctly. I hope someone can identify what

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