I have a UN50NU6900. I normally use a wired connection. I have several streaming services and all will occaisionally stop working, wired or wireless. The TV will tell me that there is no internet connection. I have to reset the TV or switch to the other connection (for ex., wired to wireless).
I was checking out youtubeTV's "stas for Nerds" when the connection dropped. SfNs showed that there was 20Mbps bandwidth available, but no network activity. It seemed the connection was available, but the TV wasn't accessing it. I was able to confirm that the network was up by pinging the TV from another device. Other devices on the same router were also able to connect to the internet.
This is an issue internal to the TV, not a problem with the network.
I am running Software version T-KTSUAKUC-1310.4
STATUS CODE 0000020000000
Sub-micom Version T-KTSUINTV-1004