Are you a NOW broadband customer?
What do you mean your Wi-Fi won’t let you watch next episodes?
Are you able to use other apps on it?
What sort of device are you using? As you’ve mentioned Smart TV but also just NOW TV which would infer a NOW branded stick.
Is this a 2015 Samsung TV? Now stopped supporting those in September this year.
If not, can you please give the model number of the TV, who your broadband supplier is, what package you are on, and what speeds you are getting?