Lots of people are having the same issue, including me. We were discussing in this thread:
But sling team thinks the problem is our router. Worse than that, they closed the thread previous, which ****** me off.
They don't understand that it was working before and keep blaming the router. I have port forwarding in my router and still does not work.
TCP is failing for both of your units. Everyone having connection issues when attempting to stream to a connected device, please refer to this thread:
Sling Media Forum Moderation Team