Elevation (alitude) and Solar issues on Fenix6X Pro Solar

You have to contact Garmin, i had same issue with 6X Pro Solar: suddenly solar charging stopped to work. 

Thanks for your quick reply. I will contact them.

I don't know your history of altitude problems so I'll just comment on what you have posted here.  A course of 22km that has a total gain/loss of about 70m over the course, is very flat.  If every time your elevation changes by 1m the watch interprets that as 2m, or your elevation doesn't change at all and it interprets there was 1m of change, that would explain what you're seeing.  This isn't a laboratory instrument, its going to have a small amount of error, and the course you're running is going to accumulate that error worse than most.

Have you tried the same course with a different brand watch, and if so, was it able to provide more accurate results?

Did a quick comparison on my usual 10.633 km course.

• According to the added course in Garmin Connect the course haves 158 meters of Elevation Gain and Loss
• Garmin Fenix 6X Pro Solar Titanium shows 115 meters of Elevation Gain and 119 meters of Elevation Loss
• My old Garmin Forerunner 310XT shows 163 meters of Elevation Gain and Loss

My 2 cents is that the Forerunner 310XT is more exact than the Fenix 6X but I cant prove it more than this. 

Update. After enabling the Elevation Correction feature in Garmin Connect I've got 160 meters of Elevation Gain and Loss on the Fenix 6X. So, it measured the elevation rather wrong within the activity.

Not necessarily (and it’s weird why)

when you plot the. Course it will lock the elevation to the underlying DEM.. The data the map has on the underlying terrain. This data is quite coarse and may be at a sampling of tens of metres.

without EC on, it’s using the inbuilt GPS. Now, that may be out, but it’s possible it’s right. Depends on the gps conditions there.

switching EC on, it now locks your path to the same DEM as the route, and the only differences may be where your x,y position slightly wander. In places this may result in small discrepancies over a long distance as you occasionally wander into a position where the DEM height of your x,y is different to the route (on the edge of a sampled segment)

Yesterday I was running 10km, just 5km forward and 5km backward, so exactly the same. And the profile shows otherwise. I have contacted Garmin, but no response yet.
I am living in a pretty flat country (The Netherlands, I have to search for a place with elevation) :-) 

I am gonna test it out today with some other watches too that I have. The corrected elevation profile in Garmin is not really a point to compare it with I think. Like AJR mentioned also. But it can be useful to think about it. The elevation profile when running for- and backward bothers me. As an example, I did run a 20km on 4th of June, Fenix watch gives me an 355m elevation, with correction enabled it is 50m of elevation. While this is a too big of difference because it was also a flat course with almost no hills.

Yep. That’s GPS issues. Even with barometric altimeter, it’s never spot on, you’re always fighting errors. Your case shows a lot. If you locked to the DEM it would fit the map in GC but does it fit reality. Running forward and back on a nice 5k ish route should show a degree of symmetry, and the deviation from that symmetry will be GPS error related. Barometric pressure changes will affect this as well.

Which calibration settings do you got for the Altimeter in the watch?

I've got "Auto Cal." configured like "During Activity" = "At Start" and "Not During Activity" = "On"

A lot of people had problems with "Continuous" calibration setting before. So, I changed that to "At Start" and then the Elevation profile starting to look good. But it still measures the elevation changes to small I think. 

I have set it to Continuous, I will try it on at Start if that will work for me.
And I have also "Not During Activity" = "On" 

I have calibrated the Alitmeter and Barometer manually by DEM and GPS, that did not make a difference by the way.