I have a weird problem. My Ethernet port from the

Question

I have a weird problem. My Ethernet port from the

mainboard doesn't work on linux anymore (No linux distro, I tried different ones). Yesterday it until today everything worked perfectly.
On windows it still works.... Even inside linux live ISOs where the it always worked, it doesn't work anymore.
What does not work:
I can't establish a connection with my home network (With a USB ethernet card it works). dhclient gives me a reserved IP address (starting with 169 or 167 iirc) but my router doesn't recognize the connection.
NetworkManager and Connman keep stuck at 'connecting', dhcpcd configures the device but I still have no Internet access, not even with a static IP. Booting Arch linux stucks at systemd doing a dhcp request.

I tried:
-> Booting into various linux distros (arch live, artix live, even kali since it has some good driver patches)
-> LTS kernel, Zen, Xanmod, Stock kernel (on artix)
-> Booting without efi into a live ISO
-> Exchanging the ethernet cable
-> Resetting my routers configuration for the used MAC address
-> Changing the mac

I'm really out of ideas. Has anyone an idea?