I use a pair of LG Infinum headphones to listen to my audiobooks and podcasts. I leave it at my desk at work and can walk around the office, open area with a few walls here and there but just cubicles mostly, low and high ones. Never had an issue. Walk around with my headphones around my neck, the phone in the pocket of my shirt and backpocket of my pants and no issue eithier.
The one time I had an issue with my G3, it was the pairing didn't go right. Unpair and repair next to each other, see if that fixes it.