Netgear C3700 Samsung Smart TV - can't use apps

I have a refurbished netgear c3700 router (bought on amazong less than 3 months ago). I have a Samsung Smart TV [Model: UN48J5201AFXZA].

Everyday when i turn my TV on, I am NOT able to automatically connect & startup Hulu/Netflix/Amazon Video/etc. On the tv, I have to navigate to Menu - Network - Network Status -- IP Settings. It always says "connected to the internet" but once I select a video streaming app from the samsung smarthub, i get an error saying "preparing tv, please try again"

So then I go to IP Setting, change DNS Setting from "obtain automatically" to "enter manually" -- and i manually enter 8.8.8.8

the next screen shows a message saying "connected to the internet" and now when i select a video streaming app from the samsung smarthub, it works! but the next day the same problem arises -- except that i have to switch from "enter manually" to "obtain automatically".

I have time warner/spectrum internet in Manhattan, NY area. When I called they said it could be either a router issue or an issue of the tv (not helpful).