Erratic Wrist based Heart rate : BUG + Root cause

Not a solution, see my post above. It happens with a chess strap (from Garmin)…

I don't think your observation with the chest strap is related. But it is even possible to get cadence lock with a chest strap in very rare cases.
Maybe Garmin will make improvements to the sensor software.

Just saw your post, thank. But from picture with HR alone, without having any extra context, like pace and elevation for example, is difficult to extrapolate meaning.

Hi All,  

I have had this watch since July, 2022 (almost release date actually). 
I am a middle distance runner competing in 1500m and I am having those problems too, with any firmware version. 
So much money for inaccurate measurements (hr, altimeter, temperature). 

If it helps you can also take a look in my activities or even contact me for details @Garmin-Sierra
Hope we get a solution on that..

I have the FR 255s.  And I have a HRM Pro+ so I have compared the two.  I also have an old FR245 so have worn that at the same time as the strap connected to the 255.  I would agree the wrist sensors are not as good as the much more accurate chest strap. But the main error I see with the 255 is during activities the watch is way over reporting Max Heart Rate. Even during low movement activities like weight training or yoga, the max heart rate when wearing just the watch will be way too high.  I have seen it jump as high at 180 when a manual check will show my rate is really closer to 110 or 115.  It only jumps up like that occasionally and almost immediately comes back down so I believe it is just something in the way the wrist sensor works or does not work.  Interestingly when I look in Garmin Connect at an activity the max heart rate for that activity is usually reported differently depending where in GC I look.  For example, in a weight training session on Saturday, the activity itself shows a max heart rate of 178, Looking at Saturday overall in my health stats however shows a max heart rate for that entire day as 132. If I look at a max heart rate report, that shows the erroneous 178 as the max for that day.  Weird.

Overall, I think these watch features are more useful for entertainment rather than actual health tracking.  I know my sleep statistics are pretty inaccurate also.  And the step counting feature of the watches, which Garmin told me just use an accelerometer, can also be wildly inaccurate.  For example, if you hook the thumb of the hand with the watch on the strap of your backpack for a mile when hiking. very few steps are recorded.  Another time I had the watch on the hand that was controlling a backpack leaf blower.  Every time I swung my hand back and forth a step was recorded.  In an hour I went from about 3,000 steps to over 25,000 steps.  In reality I probably took a max of another 3,00 steps during that time, not 22,000.

It's been a month now. When will it be sent?

Dear Sierra,

Would it be possible to revert to the latest stable version?

It is true that is part of the risk of being a beta tester, but correct heart readings and evaluation of burnt calories is the very value proposition of  a sport watch.

Garmin is the market leader, personally is not a matter of frustration, it's a matter of trust.

I am available to be reached via email.

Thanks