Heart Rate monitoring unexpecdly drops to low values during workout

Same feeling here also..   It happens with the ANT+ strap, batteries new, and had no issue before .

Same here, never had that before. Have a hard time accepting that this is a software thing, but HR dropping mid-run by 60 BPM for 10 minutes is odd. The HR strap is fine, not worn out, never had a problem, battery status "new". Will keep an eye on it and report it as a bug if it is consistent across many runs and more than one HR strap.

Update 8 days later: I noticed increasing amounts of noise in the HRV graphs in Runalyze, and replaced the strap although it was not visibly worn out. It  solved the issue for me, so I guess it wasn't due to the update after all.

Yep same, it was definitely reading 100 while my HR was at least 180 measured with a wristwatch during a backcountry ski activity today. Never did that before.

Same story here, before the update it worked perfectly fine. Hope they will release a fix and get back to normal.

I tried a few things backcountry skiing today. The "Track Me" and "Trail Run" profiles seemed to give the same problems. I switched over to "Bike" and it worked perfectly. It's definitely a software issue.

Hi everybody, i'm having same issue but only with whirstl sensor. The chest band is working fine. It does randomically on my apps and also on other apps from different developers. At first i thougth it was my hairy skin but shaving didnt solve. My watch is a fenix 5x plus but i have feedback from 7x too with same issue. Unfortunately reboot didnt solve too...:-(

my fenix 5x has firmware 18.00

i forgot to say that for my fenix 5x plus it happens after 15/20 min of activity at high HR rate... over than 130 bpm. If i remain under 130 or check the app when i'm not doing activity it works fine!!

Same problem here. 

After using the watch + chest strap for the past 2 years, multiple events etc... havent had an issue until this latest update (24.10). Thanks.