Have you tried to watch content on your mobile device to activate your sports membership?
Also it’s no longer called “Now TV”, as of last week it’s simply “NOW “.
Apart from a colour makeover and dropping the “TV” from the name, the app is almost no different than before in my personal opinion.
Have you tried to log out of the devices and log back in? It might sound elementary but you could restart your router as well.
Also you could head onto live chat and speak to NOW staff. Just make sure to click “chat online”.