I use an edge 830, and an iPhone that it’s paired to for live track. All works fine and I get the audio prompts for navigation or every lap as expected. However, a friend I’ve just started cycling with happens to ride with wired apple ear buds connected to his iPhone, which is paired to his Garmin Fenix 5. He’s never paired or tried to pair with any of my gadgets - but if he’s close enough to me when an audio prompt is sent to my phone from my 830, he gets the prompt in his earpiece. (It even decreases the volume of the music he’s listening to briefly)
How can this happen and does anyone know how I can stop it? Seems like a bug but a bit of a security flaw too?