Altimeter/Elevation (yeah... that again)

Similar problems with MTB (where speed is less an issue, but elevation gains are more meaningful). With 4.20 on a 5 Plus Sapphire I experienced some improvement with the altimeter: round-trips show now the same elevation at the beginning and at the end of the ride (with 3.20 I had deviations of up to 250 meters after 3 hours!). Yet the total ascent and total descent remain both too low, (up to 250 mt. lower than they should be, out of a ride with 1.300 mt. real elevation gain!), and, even worse, they differ by as much as 100+ meters (while for round-trips they should be aligned). Still during the ride (compared to a garmin EDGE 1000 mounted on the MTB) I see significant fluctuations (generally with elevation shown by FENIX lower than elevation shown by EDGE, oscillating between few meters at the beginning, then rising to 30-40 meters, and then going down again to acceptable differences later on). I set the barometer in "ALTIMETER" mode, and "continuous calibration during activity". I am an happy user of EDGE 1000, but very disappointed about FENIX 5 Plus ... for such a basic functionality such as altimeter! I hope they will focus on fixing quickly these issues (that should have been fixed with 4.20!), rathen than improving the UI of the Music feature!

Similar problems with MTB (where speed is less an issue, but elevation gains are more meaningful). With 4.20 on a 5 Plus Sapphire I experienced some improvement with the altimeter: round-trips show now the same elevation at the beginning and at the end of the ride (with 3.20 I had deviations of up to 250 meters after 3 hours!). Yet the total ascent and total descent remain both too low, (up to 250 mt. lower than they should be, out of a ride with 1.300 mt. real elevation gain!), and, even worse, they differ by as much as 100+ meters (while for round-trips they should be aligned). Still during the ride (compared to a garmin EDGE 1000 mounted on the MTB) I see significant fluctuations (generally with elevation shown by FENIX lower than elevation shown by EDGE, oscillating between few meters at the beginning, then rising to 30-40 meters, and then going down again to acceptable differences later on). I set the barometer in "ALTIMETER" mode, and "continuous calibration during activity". I am an happy user of EDGE 1000, but very disappointed about FENIX 5 Plus ... for such a basic functionality such as altimeter! I hope they will focus on fixing quickly these issues (that should have been fixed with 4.20!), rathen than improving the UI of the Music feature!

I plan on getting on the MTB next week and will take a look. I'm not sure if it's a function of just my watch or if it's a software issue, but I'm leaning towards software as it still seems to be popping up here and there on the forums.

Just today I arrived at work after my first ride and elevation was at 593. It should have been at 617. Within a few minutes after the ride, it drifted DOWN to 555 instead of up. I've washed out the watch to make sure there is no debris in there.

What I also find interesting is that if I'm moving a fast rate and not in an activity, the watch face doesn't update often UNLESS you hit the START button and then the BACK button. Then it will update regularly until the backlight goes off. Not sure if it starts to auto calibrate thinking you are going into an activity or what...

I'm going to try riding with the 5 plus and my wife's Vivoactive 3 soon to see if I get the same results on both (both have updated firmware to fix the smoothing issue). Maybe that will help determine if it's the watch or an ongoing software problem.