My issue is that HR works fine part way into an activity and then will drop sometimes down into the 50s while my HR is still between 130-150.
Sometimes it will recover sometimes I start a new activity and it works again.
I don't expect it to be accurate but this is unacceptable in a fitness tracker. It wouldn't be so bad if I could edit the data afterward but it is useless as is.
Troubleshooting
Hard reset
Adjust band to various tensions
cleaned the sensor
tested indoor and outdoor activity
compared with another wrist based fitness watch / then switched arms
So I called Customer Support because this issue seems to be getting worse , especially around the last update.
He looked at my profile and then offered me a discount on a refurbished fenix 5
What is funny about this is the price he quoted is only slightly less than I can find a new fenix 5 online
I have been reporting issues with this watch nearly since getting it. Yet now that it is out of warranty they are offering to sell me another one.
Shame on you Garmin!!!!!