For the last couple of weeks All 4 has refused to load on my Samsung TV. I've never actually watched a programme on the app but I have had it open before and browsed programmes. But now all I'm getting is the colour C4 logo with the various channel logos below in white and below that "Paid for by advertising. Owned by you". And four squares ticking away like egg timers on dial up in 1995. I've checked the latest software is downloaded. I've tried the other apps in the "hub". It's only All 4 not working. I want to watch the Handmaid's Tale, but it would appear I can't. What's the likely problem ?