Low Heart Rate Issue Continues with Software v17.23

The reason I ask for the weather conditions is that I noticed inaccurate HR in winter with low temperatures. Whenever I went outside for a run with my watch exposed to the cold, I would have low HR. When I went outside and I covered it with a jacket, the readings were according to expectations.

This is one of the Garmin explanation and bugfix were release for this concern, but again i  never encounter this issue with Fenix 6 Pro. I can't imagine covering my watch not seeing the screen of a 800€ device.

And it's not very practical for Course Navigation ;-)

When it is working with older devices newer "best of the world" product should not imply a regression in the user experience.

I had very low to no readings at all in the first winter after buying the watch, and covering the watch (or high intensities) would help. This problem is very different.

In this case (since two or three updates back) it happens in all weather conditions, even when covered and is not consistent between and during rides/runs. It seems to also depends on the type of sport how the problem looks like:
Cycling is my main sport, for most of the time Z1 and Z2 seems fine, until I have to stop for for instance a traffic light, after this it sometimes gets stuck at around 90-100 for minutes. Also after a longer pause it seems to sometimes need minutes before giving correct numbers.
But the worse parts are intervals and longer Z3-Z5 efforts. If at the end of a Z2 ride (around 130 bpm), I do a sprint up the (15m high) bridge next to my work, my heartrate tends to drop from 130 all the way to 90-100 bpm, and only goes quickly back up to 120-130 after a few minutes of Z2.

In running my heart rate is normally a bit higher, let's say 160 bpm, here it seems to take at least 10 minutes before it gets here, where at the first 5 minutes it  seems stuck around 120 bpm.

In walking it seems to work fine, around 100 bpm.

In (outdoor) rowing it seems to work fine most of the time, with some spikes up and down, which only result in the watch thinking I'm doing anaerobic intervals, when I'm just doing a steady pace.

I was first advised (By garmin support) to turn heart rate off, soft reset watch, turn heart rate back on. This seemed to work at the beginning of the first ride, but during that ride the problem came either back again or was not solved at all (hard to know, since I'm not measuring all the time with two devices, but the sprint to the top of the bridge is a kind of test that works everytime by now).

Now I got the advice to connect the watch to Garmin Express, apparently this updates different things than the over air update (WiFi). Let's see if this does anything. I'm getting at the point that I'm almost out of warranty, so want to know if I should ask for a replacement/repair or that it is a software issue that will be solved.

jorisadmiraal said:

Now I got the advice to connect the watch to Garmin Express, apparently this updates different things than the over air update (WiFi). Let's see if this does anything. I'm getting at the point that I'm almost out of warranty, so want to know if I should ask for a replacement/repair or that it is a software issue that will be solved.

I assume issue is device dependent.  Because there are likely many units out in the field, and not everyone has this problem.

I just contacted Garmin support.  They are going to swap out my watch with a recertified unit.

I have done close to 50 tests over past 2 months.  And I'm wearing 2 different Garmin watches at same time to compare.  External conditions are not factor (or cause) in my case.

I have done soft reset and hard reset.  Soft reset does nothing.  Hard reset means wiping the device completely and going to default settings.  Yes, hard reset fixed the problem immediately.  Then I proceed with step by step setup.  That is when I found out my issue occurs when headphones are paired/connected.

So hard reset is something you can consider. But at some point, you want to set up the watch to how you use it.

Based on your other post where you reported the correlation with headphones, I did some test with mine.

I do not use headphones, so that's not an issue for me, but what I usually did was syncing with the app before a run (to get current weather data).
I stopped this routine and did not have any issues with heart rate anymore, I then did a sync once and during that run, the heartrate was unrealistic in beginning with a sudden step after a while.

Last test without previous syncing showed no issues again.

So this is not a scientific test series so far, but assuming this hardens over time, then I would make the conclusion, that the erratic behaior is related to Bluetooth activity, like with your headphones.

Update.  There is some other setting conflict combined with headphone (bluetooth) causing this on my watch.  And v17.23 is "better" than v16.22 in occurrence rate.

On v15.77, I had around 8 occurrences of low HR in over 60 runs. The occurrence rate is quite low.  Just looking back at the data.  It was hard to detect, and depends on my pace and actual HR, because I didn't use another watch to compare.

On v16.22, the occurrence is around 90% of time when using headphones.  And I'm quite certain on this, as I was comparing Epix Gen 2 with Vivoactive 4.  After I noticed the headphone dependence, I stopped using headphones for 1 months, and had zero issue.

On v17.23, I resumed using headphones to test it out.  First 2 runs were fine; then 3 runs with issue (confirmed headphone dependence by toggling headphones on/off); now 2 most recent runs are fine.  The only thing I did recently was I used a built in watch face for a day, and then went back to same 3rd party watch face I have been using.  

I have an incoming replacement watch from Garmin.  So I have to test both watches quickly and decide.  The replacement is recertified, so could  be refurbished or returned.  So I prefer to keep my watch (which is only 4 months old).

Did a 1/8 Triatlon yesterday and during the cycling I had both my watch (wrist sensor) and Edge 510 (coupled to my chest strap). Since the swim + transition should be more than enough of a warm-up, I was surprised my Epix Gen 2 was still struggling, until minute 25 (or about 13 of cycling), after that it was almost spot on again. Around the transition it had a dip again, during the Run it seemed all fine, (reached even my max heart rate), but have no dual recording of that part.

Most interesting part is the transition. My phone was in my bag next to my bag and it seems my heartrate of my Epix Gen 2 goes down from 150 to 130 the moment that I arrive at my bike, where you can see that my heartrate measured by the sstrap is much higher when I start cycling. It seems that Bluetooth connection influences the heart rate measured by the watch and even worse, that it takes about 10 minutes after loosing connection before the "correct" heart rate is measured by the watch.

jorisadmiraal said:

Most interesting part is the transition. My phone was in my bag next to my bag and it seems my heartrate of my Epix Gen 2 goes down from 150 to 130 the moment that I arrive at my bike, where you can see that my heartrate measured by the sstrap is much higher when I start cycling. It seems that Bluetooth connection influences the heart rate measured by the watch and even worse, that it takes about 10 minutes after loosing connection before the "correct" heart rate is measured by the watch.

Good work.  In both yours and my cases, there seems to be bluetooth dependence.

Please share this data and finding with Garmin support.  When I contact Garmin support, they just treat this as one off.  They search their knowledge database for headphone conflict with HR.  It seems to be higher level issue with bluetooth.

Hi, so as far as I understand for you the optical HR measurement was ok until software version 15.xx ?

If that's correct it hopefully means that it's only  a software issue.

What I can't understand is that garmin is not able to roll back the software to that old version before 15.xx concerning the wrist heart rate measurement?

And they even claim that the new Elevate gen 5 optical sensor is much better than the old gen 4 from Fenix 6 pro? The problems they obviously have with their software to improve the optical heart rate measurement tells me that the problem is bigger and it is a combination of software and hardware.

And finally I have the  impression that the new sensor wasn't tested enough before it's release and now the poor engineers have to improve it on the run. 

Also with trying to combine wrist and ecg belt sensor I think Garmin is trying to collect data to improve their optical hearte rate sensor software for the new gen 5 sensor wit some AI algorithms. That seems somehow desperate because if the gen 5 were really better than the gen 4 it wouldn't be so tough for them to solve those issues with optical HR measurement with Elevate gen 5.

Question is if also the Venu 3 with that sensor has the same issues? If yes, I would claim that it's definitely hardware!