Hi everyone!
I'm using a Forerunner 965 with an HRM-Pro+ for running. Very often (almost every second workout) I experience 1–2 short periods (2–5 minutes) where heart rate data drops out completely. According to my observations, this mostly happens during my intense sessions, especially when I'm sweating heavily. It also happened twice yesterday while running in the rain. I’ll attach a screenshot to show what it looks like. Any idea what might be causing this?
Thanks!
i hade even more severe behaviour. my grapf had no data for half of time.
than someone here on forum suggested me to turn off source switching. And this for me, looks like it solved the issue.
Disable source switching and connect to the watch the strap via bluetooth, and see if its improving
Also unpair and re-pair the HRM . There was a change in a recent FW that had to adapt to new legislation on encrypted / open connections and i had issues until I deleted and re-paired the HRM
One more interesting example. Screenshot from Garmin connect:
But when I export this workout to a .fit file and open it in a viewer, I see two different heart rate values, and I don't understand why this happens.
So the system records heart rate data from both the wrist sensor and the chest strap, and in some situations, it gives priority to one over the other — or am I wrong?
Thanks for the advice, I’ll try it in my next training session 
