This is an observation from days/weeks of careful triage. Anyone out there have a solution, I am all ears...
I have been trying to get Spotify to work natively on the Q950T as is advertised by Samsung. Since this Soundbar system is enabled with Alexa, which works fine for the most part, trying to use Alexa to play any Spotify music isn't exactly what they say it is. When I issue an "Alexa, Play Music" or anything similar... Alexa responds with "Here's Spotify..." and then nothing happens. No music is played, no error... just silence.
The only way i've gotten Spotify to work with the Q950T is using Spotify Connect via the Spotify app. In the SmartThings app if you click on your Q950T, and then the 3 dots in the top right, you can get to "Spotify Settings", which has Spotify Connect instructions that say "Use your voice to control Spotify".
HOWEVER, that is exactly what does not work. You can either click "Link to Spotify" which opens the app installed on your phone...(genius Samsung!) note: sarcasm. OR just open Spotify on your phone and use the Connect method to play off the Soundbar. Either way, it is manual... and NOT Voice activated like Samsung advertises it.
Bose, Sonos etc. can claim true Spotify integration. Samsung just rolled out another sub-par "feature" on their "top of the line" Soundbar.
Coupled with some other issues I have experienced and noted others in the forums reporting too.... this "top of the line" system is in desperate need of some bug fixes and firmware updates to bring it to its potential.
So this seems to be a case of misleading advertising. What I have found (and confirmed) from the HW-Q950T manual Page 34, is that you can issue Voice Commands to Alexa, but it's limited to only the Amazon Music service. Those of us who have Spotify as our default service in Alexa cannot use this Soundbar as a true streaming player (like Bose, Sonos etc.). For the Q950T, you have to use Spotify Connect from the Spotify App. Try voice command "Alexa, play some Jazz on Amazon Music". The soundbar should accept command and play off Amazon Music.
If you read the most recent reviews from Amazon Alexa Spotify Skill: https://www.amazon.co.uk/product-reviews/B07FK56GVY/ref=cm_cr_arp_d_viewopt_srt?ie=UTF8&filterByStar...
You'll see that Alexa is causing the problem, multiple people have the same..
Well... except you are not enabling the Spotify skill on the Samsung Soundbar, you are enabling Alexa voice assistant.
If you try to connect the soundbar to your Amazon account via SmartThings, it actually says that this device was not tested with Alexa.
I have a Bose sound speaker which comes with similar setup. On that, the app actually allows you to configure music services (such as Amazon Music, Spotify). The complete lack of this option on the Q950T itself tells me that the device can’t support it.