I resolved the problem by adjusting the audio settings in the Bose app that I downloaded. I increased the Surround Level to 10+ and decreased the Center Level to 6- and finally got the sound from a TV channel to come out of the rear speakers.
Great! Glad to hear that you've found a resolution.
If you have any more questions, please let us know 🙂
Best Regards,
Brandon - Bose Support