If you are in "phone free" mode, you won't be able to adjust volume. Cancel the mode, set volume and then (if wanted) restart phone free mode.
Thank you for reaching out to the community. Have you tried removing and reinstalling the Bose Sleep app on your device?
The phone-free mode enables you to use your Sleepbuds without having your phone in the same room where you sleep. Both alarm/sound settings are disabled. Tap the gear icon and you should see this option under Settings.
When enabled, the next time you open your app, you will see an option that reads " Disable Phone-Free Mode."
Please let us know how everything is going when you get a moment.
Thank you again,
Mohsin - Community Support