Heart Rate Drops with HRM 200 on FR965 – How to Fix?

I have a FR965 and when running or doing other activities I keep losing the heart rate from my hrm 200. the heart rate suddenly drops with 30bpm and goes up again after a few seconds.

I have tried connecting the HRM200 with ANT+ and BLE. both connections give the same problem.

does anyone have the same problem?

anyoe know how to solve this?