Same issue, TV is a little over two years old and out of warranty, Samsung customer service will only take any positive action when they see another opportunity to extort money from the consumer. This is the first Samsung TV I've owned which was based on a recommendation (we are no longer friends). My advice is to treat this as a hard lesson and buy a Panasonic on move on, personally you couldn't give away another Samsung product to me. Pound shop quality at best and that's being kind!
Besides the dark patches on the right side of my Samsung 2015 48" Smart TV, they stopped updating apps more than a year ago, no new apps (new services are available which work on my 32" Hisense) and there was no update for the TV since 2017. So I assume that, as with their phones, the only support their products for 2 years. Add to this that their products are more expensive and their warrantee is shorter that most other products. I have learned from experience to stop using their phones, and will now apply that to all their products!