Oct 20, 2017
Thank you for joining the Community.
I found a discussion on the Samsung forum. It looks this behavior (play alarms through the device speaker even you have connected headphones) is controlled by the Android operating system. Please follow this link to the Google Issue Tracker for more information.
You may have to pick a ringtone you can hear even when you are wearing your QC35 II. If you find one that works, please let us know.