Hi @TomB68,
Welcome, and thanks for reaching out here in the Roku Community!
We understand you're having difficulty playing Spotify on your Onn Soundbar. We'd be glad to help. Just to clarify, are you using the Roku Mobile App to control the soundbar? If so, try uninstalling and then reinstalling the Roku App back again. Additionally, can you please provide us the serial number of the Onn soundbar so we can take a closer look?
We are looking forward to your response.
All the best,
Emman
Emmanuel-D.
Roku Community Moderator