20.26: No altitude change during activity (recorded wrongly as flat with 0m elevation)

Hi everyone, I've run into a problem with my Garmin Forerunner 955 after updating to firmware 20.26. Yesterday, during a race in hilly terrain, the altimeter got stuck at a single value:

The issue was also visible in the altimeter widget. While it was measuring normally before and after the activity, during the race (where other runners' watches measured about 150m of elevation gain), mine showed a flat line.

I ran the race using the Run profile with PacePro enabled, but navigation turned off.

This seems like a newly introduced bug, as I run often and this is a first time I have seen it, right after updating to 20.26.

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0 7312496 2 months ago in reply to WillNorthYork

On my side I’ve done a recalibration on the Watch using gps and the following run it worked.

Follow-up on next one

0 DaveCB 2 months ago

I have this issue too, the first event was on 9th September just after the 20.26 update. Prior to that i was on 19.18 and never had an issue.

I do 2-3 walks a day or maybe 2 walks and a run, sometimes none of them register elevation, sometimes all of them will or just one won't,

I always let the GPS lock on before starting my activity.

GPS is ALL+Multband

No all zeros in subsystems

0 skier65 2 months ago in reply to WillNorthYork

The workaround I'm currently use is to Set Up the Altimeter calibration Not on Auto. In this case everytime you start an Activity the Wach ask you to calibrate the Altimeter (I'm usuing DEM for example). I test this woraround several times succesfully.

0 martinleroux 1 month ago

Yesterday I had a conversation with a Garmin US support rep about this. I guess quite a few people must have complained, because she said that it's a known bug. That's progress compared to another conversation with different rep two weeks earlier. In the earlier conversation the rep claimed that no-one else had reported the problem, which was clearly untrue, and she tried to fob me off by saying that I needed to check for a blocked sensor, which of course wasn't the issue.

In yesterday's conversation the rep said that one could avoid the problem by adding an data field to display elevation, as others have suggested above. In my experience that helps reduce the incidence of the problem, but it doesn't always work. I've still had this issue on at least one occasion even after adding an elevation data field.

0 6106907 1 month ago in reply to martinleroux

I got a suggestion from Garmin support asking to start, stop, discard, before starting your activity for real. So far this has worked for me. It's a little annoying to have to remember to do that each time, but so far, 12 activities in a row had elevation working.

0 DaveCB 1 month ago in reply to martinleroux

I have distance, timer, time, elevation, total ascent, and pace as default screen on my walks and ive experienced the error at random.

0 z-paul 17 days ago

Still the same issue on 21.19 :(

0 juza 15 days ago

FW 20.32, spot on.