Hi @Anonymous User
I don't own a Samsung Smart TV, but a couple of things that i would try.
Unplug the power to your Samsung TV at the electrical mains, at the same time you may has well reboot your Router (even if the other Apps are running fine on your television).
Let the Router start up first (give it say five minutes) then plug the power back in for your television.
If that doesn't make any difference, maybe try a fresh NowTV App install from your television Apps Store.
Should your television have a Lan port and it's practically possible in your home environment, then run an Ethernet cable rather using WiFi where the NowTV App seems to struggle more than other Apps when it comes wifi operating performance.
Other than that i am out of ideas.
