I have a few years old Samsung QN65S90 and been using YouTube TV app for a year perfectly.
All of a sudden the app won't allow me to play any shows. It goes black.
I have called Samsung and YouTube TV support and still not working.
yes I have powered on and off. Deleted the app and reloaded. I have restored TV to factory Default and still not working. App working on my phone and Roku TV. Just this Samsung TV all of a sudden.
Fixed the YTTV problem by installing an Amazon Firestick into an HDMI port, and then simply used the Firestick remote. We stream all the providers (YTTV, Amazon Prime, Paramount, etc., etc.) through it. YTTV has worked fine ever since, and we get all the Amazon free TV channels. The Samsung remote has been in a drawer for about a year or more.
Not really a fix but a workaround, and still very annoying that Samsung doesn't bother to respond nor fix the issue, requiring not using the Smart TV functions we paid for, and having to buy an alternate streaming device.
