Fluctuating Watts

I have a Kickr Core, My Zone HRM and connect via Bluetooth to Apple TV/Zwift with no problems at all. When I’m in Zwift training mode, Cadence and Watts are constant readings however, my HR will fluctuate every now an again and read ‘0’ for an instant and then back to actual HR. When I’m just riding, cadence and HR are constant however, Watts will fluctuate, if I’m riding at a constant Cadence at around a steady 200 Watts, the Watts number on the Dashboard will fluctuate every now and again, dropping around 50 to 100 Watts and then back to the 200 Watts number.

Is this an issue with Bluetooth? Is there are a way I can connect directly vai a ANT+ cable to the Apple TV? Suggestions, comments greatly appreciated!!