Wonder why people are suggesting assigning an IP and if it works go back to auto. Your unRaid server should be given a static IP and it should stay that way. It is a server, you don’t want the IP changing. I got rid of my provider router and put my own in. Did you get this resolved yet? Since it connected to your Linux server fine with the same cable, you know the cable and server are fine and it is a problem with your router.