Hub won't register

I have searched everywhere and taken all the advice I’ve found but my hub will still not register. I’ve done hard reboots, I’ve reset my home network, turned off firewalls, tried with WIFI and ethernet, with and without the wifi on my phone connected. no matter what I do I get to the registering Hub screen and end up with the can’t register device warning…HELP???

sorry, its a 6001 3rd gen samsung smartthing hub