Pretty sure your developers are aware of Tizen's existence.. 🙂 So rather than pointing them in the right direction I would like to ask when will they start getting there. Spotify and Samsung, two titans in their own playing field. That's a no brainer!
I have multiple 60+ inches Samsung TVs with Tizen and was disspointed to learn there was no player after getting a 4K TV. This has been going on since 2015.
Spotify, use to be really good about having players on multiple devices, like Samsung, Roku, etc.. it's strange like Spotify doesn't have enough money/resources to create players. Samsung is a large player in the market.
Reboot your TV by holding the power button at least for 5 secs and try again. You should see the SUHD / Samsung Quantum Dot logo. If you release the power button too quickly, then you're putting the TV in standby mode.