Fenix 6 wrist HR massively inaccurate again after v15.20 upgrade

A easy 10k this morning with the 15.71 beta code, and it's just as bad.. HR started out normal but after 15/20mins it was reaching new Max HR levels and it stayed pegged at max for the rest of the easy, conversational paced run. I have opened a case with Garmin as well

LeeB25 said:

HR started out normal but after 15/20mins it was reaching new Max HR levels and it stayed pegged at max for the rest of the easy, conversational paced run

This thread has several different problems mentioned, but reading your post specifically it sounds like you may be experiencing cadence lock. Have you explored this possibility? 

This has been said on many occasions. Garmin constantly 'tweak' the code to get better results for more people. Unfortunately that might mean a change in behaviour for some. The start point to avoid what appears to be cadence lock is to ensure your watch is fitted well clear of the wrist bone and tightened a notch or two more than perhaps you have it usually.. As you run you sweat more and the watch can then slip to the point where it becomes less snug and bounces.

What I noticed after the last runs is that the HR become more stable after I adjusted my Vmax according to the data I was getting. (= changed in my case Vmax from 186 to 193).

Unfortunately I don't have a strap to check for the true values, but at least consitency is better for trending.

Can you confirm what you have actually changed? My HR is now verging on useless.

I have raised a ticket with Garmin and will be expecting the standard excuses. 

On my run today, wrist heart rate worked fine for about 40mins, just gave up for the last 10mins! 

Didn’t move watch position on wrist, turned watch off/on and it’s working again! 

Expected more from a fenix 6s Pro after my 645 but my 645 was faultless! 

I've changed my personal setting (for example via connect app) / HR ranges => max. HR (= 100%) according to the highest heart rate I experienced in trainings. Before the v15.20 update I was hitting 186, now 193 ish).

Doing this you can at least judge the zones your're in, better.

So I heard back from Garmin and it pretty much lines up with what you said. I should use the Elliptical App when on the elliptical and not the Cardio app.  The Cardio App seems to run very high HR at times even when I'm not on the elliptical and not working super hard. That leaves me with the question, what is the Cardio app for?

Just wanted to provide an update.  Garmin sent me a NEW Fenix 6 Pro because the customer support rep felt it was a bad HR sensor.  I had a strong hunch that this would be a waste of time.  Anyway I tested the new (not refurbished) replacement watch against my original Fenix 6 Pro and it had the same spikes in HR as my original.  I tested by wearing both simultaneously, one on the right and one on the left wrist, alternately both between my right and left wrists while exercising (yes I edited profile for which wrist it was on).  What I found is that HR never was wonky when worn on my right wrist but when there were problems with spiking HR it was always when either watch was on my left wrist.  The mode it does this in is typically Cardio but also sometimes Elliptical.

Anyway after some extensive testing and too much of my time, I can say the periodic spiking HR when exercising is not a problem with my original watch because both do it periodically when worn on my left wrist.  Seems like a Garmin issue or even a "Me" issue.

Think you’re on to something. Wore on the right wrist for a 5.5 mile run yesterday and heart rate registered lower. Crazy how foreign it felt wearing on the opposite wrist!