The problem is with the watch, not the phone app and not the laptop app. It was working fine until 3 days ago but now whether it's cardio, walking, circuit, running or swimming (with or without a chest-strap heart monitor) no intensity minutes are being recorded. And yes, I am getting my HR high enough and exercising long enough for it to register.
I've tried everything: hard reset, power off/on, throwing it at the wall, updating the firmware, the works. This is my second vivoactive and very likely to be my last at this rate. Any suggestions before I reduce it to kit form with a hammer?