This same exact issue is happening to me and it started with firmware 1280 on my TV UN55MU9000. I reset the settings, the hub, and even had Samsung Support 2nd tier and a supervisor admit that the issue is with the TV software but could not offer me any help!
Apologies We make mistakes sometimes lol. If the factory reset and a Smart Hub reset didn't correct the issues you are having, service is the next option. I'd be more than delighted to look into what I can do for you Could you provide the full model and serial numbers via private message?
No, we already talked to your 2nd tier support and they offered Service also which entails US paying for something SAMSUNG broke with THEIR firmware. This is a software issue, not user error nor user caused, as such we are NOT going to pay. We ask that you tell your Engineers what is happening, do some investigating and testing on your test TVs, and provide a patch firmware. Otherwise, Samsung can offer the ability to downgrade firmware (yes I know you cant do it NOW, but a firmware upgrade to give that ability would be possible).
I recommend giving the unit an update. It should be on version 1290.4
I assume you replied to the wrong thread because the link you gave us is not the same TV that we mentioned; Not all TVs are on the same firmware.
Also, if you had taken the time to do any research at all you'd see that I posted Feb 2020 and your link is firmware listed December 2019. Do you not realize that going through Samsung tech support that's the very first thing they tell you to do?