Suddenly can’t download apps on Apple TV 4k

Hi. I’m trying to download a free app (Tablo) on my Apple TV 4K, and I just get the spinning arrow. No other apps or games, etc., can be downloaded either. I’ve reset the Apple TV, unplugged, etc., but it won’t download anything. There must be some setting that’s blocking downloads but I can’t find it. My payment method is up to date (it’s the Apple Card). Any help or advice much appreciated.