So I have a schosche Rythm+ Bluetooth HRM. Its pairs up with the watch just fine and works great. However if I run an App such as Under Armour Record and do a workout, that app seems to use the Optical Heart Rate Monitor. Has anyone had this experience? I know the stock Workout App uses the Rythm because no lights are on the sensor during the workout. But with the Record App the lights were on and registering seriously low readings.