...and to Andi's point: does the router see your NIC?
My router (Asus GT-AC5300) has a screen (browser based interface) which shows all connected devices. Sometimes when my smart lights go off, or won't power back up when I tell them to (so much for all that "smart" nomenclature lol) I will quickly check if the connection was lost.
Further on, do you have any other devices that could ping your OS/2 box?