Forerunner 965 fw 20.26 Heart Rate issues

This is a known problem and has been around since the beginning of this Summer (in fact there is a dedicated post already somewhere down below).
Garmin has not fixed the laggy unreliable WHR ever since. It was working very well in the older firmwares (e.g. last Summer so that I didn't need a chest strap anymore). Due to this (and the increased battery consumption/bug) this watch has become an expensive time keeper for me. Although GPS still works great, but let's wait for the next firmware.

Thanks! I wasnt sure if they were related or a reversion to a previously addressed bug given that thread was a bit older. And this really hit after the update for me.

With Berlin so close, I guess I just HR from my screens and use the Apple Watch HR.

After updating to the new software version for my forerunner 965 to v20.26 two days ago, my sleep score not recorded and no morning report appears. Anyone can help. Tried restarting the watch, no luck.

(The update also deleted my alarms set.)

I have the opposite problem. Before this update my HR zones were all set and made sense. Now I'm suddenly running in zone 3 for almost every run and in zone 5 above 160 bpm for threshold workouts - previously I had never been able to get my HR above 160 on the same watch. My max HR has gone up 4 points and my Garmin coach run zones don't match my LTHR zones at all. 

Garmin coach is telling me to run easy runs in the middle of zone 2 but then the green bar and alarm don't match up, only alerting when I've gotten into zone 4. None of it makes sense. 

To top it all off, I'm running more than I ever have and my endurance score is going down and every day my performance condition is in the negatives, even on days I'm setting PR's. What?!? Losing faith in this POS watch very quickly.

in this case, you need to adjust your real Max HR, and configure the zones, if not, the training will not show the correct values, to do so, go to user profile in the watch and adjust it

Normally, after updating the firmware if there is issues, a reset to defaults will help

Hi! Have you noticed any updates have helped with this? I'm having issues with my heart rate appearing to drop really low for like 20-30 seconds when I think that is not probably happening...

6 months later and this is still an issue. I don’t think I’ll ever trust Garmin again.  Unless fixed I’m going back to Apple Watch. 

This has been happening for almost exactly 12 months. I've tried everything and even contacted support. I do a soft reset every time before starting an activity. On the treadmill (which next to ski mountaineering is the only thing I do during winter), about 1 out of 5 sessions seems to be somewhat okay. In all other cases, the watch initially gets stuck at around 120–130 bpm, and after 30–35 minutes, it suddenly spikes to my actual heart rate of ~150 bpm—far too high for Zone 2.

They will never fix it, and here’s why: not enough complaints; no willingness to address the issue; the next Forerunner is probably just around the corner, so no resources allocated to fixing old problems; and Garmin Connect+ is now the main focus because it brings in more revenue. Fixing software for older watches simply isn’t a priority.

The fix would be incredibly easy—they just need to revert to the heart rate software from about 18 months ago. I’d be happy to roll back to that version, but it's not available.

The main pity is that the watch was great for the first 12 months until they started messing with the HR algorithm.

This will be my last Garmin, for sure.