I have recently purchased Archer C1200  to replace the standard hub provided by our ISP. I imagine set it up alright as the WiFi is working and all wireless devices are now connected to the internet (some are on 2.4, other on 5GHz). Unfortunately, wired connections don't seem to be working.

One LAN port is connected to the laptop on which the router was configured in the first place. It seems I can connect to the router through the cable but cannot access the internet, even though the laptop seems to appear in "wired clients" (see image). I checked the IP address for the laptop through command prompt and for the Ethernet Adapter the IP address is 192.168.1.3 so it seems to be connected and yet no internet.

I used the other port to connect a cheap hub in the upstairs rooms (in our old building the signal is hard to catch when you on the other floor). This worked perfectly before and it provided us with an additional WiFi Network when I was using original hub issued by the ISP. However, it doesn't work with the new Archer router. It shows on the upstairs hub that there's a broadband connection and on the TP-Link router the corresponding light for LAN port is lit, yet zero internet.

Any clues as what is the issue and how to fix it?