Headphones cutting out after ten minutes or so...

Bluetooth headphones connect fine initially but cut out after about 10 minutes or so...music becomes increasingly more intermittent to the point of being non-listenable.

  • Both watch and headphones are fully charged.
  • I've tried powering off watch and resetting headphones. 
  • Headphones are not paired with any other devices.
  • I've unpaired & re-paired the headphones.
  • Problem occurs even when I'm sitting at my desk with my watch as close as possible to the headphones.

Edit:

  • Problem duplicated with two different sets of headphones. 
  • Problem does not occur when connected to Bluetooth speaker. (No drop outs after 30 minutes of listening)