Have you tried to unplug your router for a few minutes?
Another suggestion would be to do the same with the TV. Unplug for a couple of minutes.
True worst case would be to set the TV back to factory settings, it is extreme yes but often fixes random bugs and gets things working again.
You could also try clearing the app cache using these steps
Sorry bud, don’t own a Samsung TV. As I did a very quick google search for clearing the cache.
There might be more guidance on the wonderful world of google?