If your headphones only deliver sound from one ear, try the following :
1. Push the jack connector all the way into the plug. Don't hesitate to push harder.
2. Try to reset the Head Tracking.
In the iOS app, press the screen with two fingers while playing your media).
On Windows, click on the little icon in the taskbar, and select "Reset Heading".
3. In case these two solutions don't seem to be working, try to connect another jack cable.