I am currently experiencing the same issue. TV is a month old. plugged several different inputs (Roku, Apple TV, Amazon Fire Stick, Computer and Sat TV) into it and still showing same problem. changed the HDMI cables and still nothing. Reset the one connect box, still nothing.
@usereOZPEQ8gUV In the meantime can you do me a favor. Try connecting your PC if you have one to your Tv. If you don't that's fine. It also looks like you have tried everything you can. Quick question did you leave the tv unplugged for a few minutes?
Thank you so much for reaching out! This forum is for support of US products and customers. As your product is a non-US model and support for these models is very limited, please seek a support team for your area. You can do so by using this link: https://www.samsung.com/us/common/visitcountrysite.html. Thanks!