The Smarttings app on Q90T TV says “No Registered Scenes and Devices”. Already tried log out and back in, even reset the whole Smart Hub on TV, but no luck. A Samsung tech says it’s not supported! I was so disappointed that I didn’t even continue with him. This TV came with the app pre-installed, Samsung website is advertising it, it says on the box that it works with Smarttings. So any help from community is appreciated 
I’m afraid the Smartthings TV app is going to be discontinued. It was supposed to be preinstalled on my 2020 TU8000 but it wasn’t nor is it on the app store. There have also been a few people here who say it was preinstalled on their TV but just disappeared without notice (probably after a firmware update).
They should either fix or discontinue it. I was on the phone with support this morning and after so many random try and failures it eventually worked, but all the devices disappeared again on theirown. I unplugged, replugged,… randomly and it worked again. But when I deleted one of my old devices from app, everything disappeared again! The only nice thing I found about it was that my Ring doorbell pops up in a small window when motion is detected, which is convenient, but that’s gone too. SMH
Yeah I wanted it to monitor the babies room with one of my Smartthings cams to only find out its not on my new TV. Irritable best describes my reaction that it was not included but decided to not go through the hassle of boxing the damn thing up and sending back to Samsung.com. Oh well, lesson learned, never go by what is advertised…