Wrist HR monitor worked fine. Then I paired with H10 external HR monitor. For running, if I ware the external HR monitor, Fenix will use it, otherwise it will use the built-in wrist HR monitor. This is great. However, for swimming, I can't wear H10 (not water proof), but Fenix won't automatically use its built-in wrist HR monitor. I tried everything in Settings, but can't figure out how to make the Fenix 5 to use its own wrist HR monitor when the external is not connected. Please help. Thanks!