Mac won't detect ethernet connection

Hello,

I have a Mac Mini and suddenly it stopped recognising the ethernet connection. I know the Internet connection or the router are not the problem as we have a second computer and a smart TV device, all of them are connected to the same router and the second computer and the smart Tv device work perfectly fine. I did all the trouble shooting, changed cables, changed the sockets where the devices were connected to and used time machine and restore the Mac to a back up from January this year, still the Mac says there is no cable plugged however it connects to WiFi and it's even able to hotspot from my iPhone.

Any suggestions would be really appreciated.

Screenshots for reference below.