The issue is identical to the one described in this thread: https://us.community.samsung.com/t5/Home-Theater/Samsung-Q900T-Spotify-Issue/td-p/1622821
The short version is that the soundbar turns on when I start listening to Spotify on another device. The accepted solution states that forgetting the device and logging out of all Spotify accounts solves this issue, but it is not the case for me. The result is only temporary, as whenever I connect to the soundbar through Spotify again this issue returns. Forgetting the device every time I listen to Spotify on the soundbar is not a solution in my opinion as this was not what this system was designed for.
After contacting Spotify they have told me this is a firmware issue and is up to the manufacturer to solve: https://community.spotify.com/t5/iOS-iPhone-iPad/Spotify-wakes-switched-off-connected-device-without...
Solved! Go to Solution.
I am experiencing the same issue with my q800t. My soundbar is turned off, I start Spotify and want to listen music on my headphones but as soon as I play the soundbar turns on, even though I'm not casting any music.
Logging out isn't really the solution because it would have to be done each time we finish casting music to the soundbar. And this is unacceptable.
I think the main reason for this is that once the soundbar connects to the wifi it can be controlled remotely via smartthings app. Something like a built in vpn. If there was a function to turn it off and allow only to control the soundbar when connected to the same wifi it would solve this problem.
Another issue is that when the soundbar wakes up this way, for some reason it won't automatically turn off after some time when there is no signal.
This sounds like a coding issue with Spotify within the Smart Things app. Essentially, Spotify turns on, checks for available devices (in this case Smart Things), Smart Things checks on its devices but instead of just checking availability, it tells the Sound Bar to turn on in order to be "available".
We have sent this up to our developers as well as tagged this thread for them to review.