While running, Heart rate bug as long as the Performance Condition notification has not been displayed

Every time I run, the heart rate displayed by my Fenix 5 plus (17.30) is false as long as the Performance Condition Notification as not been sent (usually after 5 to 10 min running).

Let me explain. My Max Heart Rate  is around 175.

  1. I start to run ==> After 1 min the Heart Rate displayed is very high (between 160 and 175), although I run very cool.
  2. So I stop ==> after 5 secs the heart rate displayed becomes normal (~110)
  3. I restart to run ==> the heart rate displayed becomes back very high again (~180) ==> I stop, it becomes normal ==> I restart, it becomes very high again.

I did this, 4 times and it is always the same.

After 6 minutes I received the Performance Condition notification ==> as the heart rate was very high, the Performance Condition is very low (today -19 !!!)

  • But, then, after this notification, the displayed heart rate becomes normal (around 120) until the end of my running.

I'm pretty sure there is a heart rate bug while the notification has not been shown.

And  I wonder if the heart rate displayed would not, in fact, be the pace, as long as the notification was not sent. Because, at the moment, I work to increase my mean pace. Usually, I start around 160 and increase my pace above 180.

Did you experience this bug ? And shall Garmin Support fix it ?