Are you starting your authentication at your ADFS server, or at the Tableau Server?
If you are starting at ADFS right now, try starting at Tableau Server instead, by going to the IP in the browser. That should set the Relay State in your SAML assertion so that it knows what page to display when it is redirected back to Tableau Server from ADFS.
If that doesn't work, I'd get a case open with Tableau Tech Support, they can take a look at the traces and your logs and sort out what is going on
I am starting authentication at the tableau server.
Ah, in that case, I'd go straight to opening a case with Technical Support, from your Customer Portal. They can help gather logs and traces and take a deeper look at what is going on.