When I connect 955 with zwift smart trainer. And want to choose a workout from the watch or just go for free ride my heart rates just drops down to 0 and is not working at all. But as soon as I disconect from the smart trainer it works again. I can still be connected to the power and Cadence meters. But not the Smart trainer. Anyone know how I can fix this so I can measure my HR while indoorbiking with my smart trainer?