X Axis measure

[tobat7]

Hello, I'm struggling with the understanding of X Axis measurement: I'm probably missing something, but in the profiles I am getting I had at first the impression that the X axis length was bigger than actual measure.
Then I compared the X axis value of a profile of a path and the $lenght data of the path and actually there's a difference: X axis says 28.453, while length is 20.312 (also on GoogleMyMaps I see 20,3km)

By the way, the Y axis is correct: it matches the altitude value I can verify also outside of QGIS.

Project and layers are set to WGS 84 / Pseudo-Mercator (EPSG:3857), I don't know if this is relevant.

Please see pictures attached.

Thank you.

[nicogodet]

No picture attached.

[nicogodet]

And attache the layer too (and DEM if possible).

[tobat7]

Here you go:

DEM is huge, please download it here: http://tinitaly.pi.ingv.it/data/w49065_s10/w49065_s10.zip
path.kml.zip

[nicogodet]

Indeed there is an issue when project crs is EPSG:3857.

And I wonder why your X axis is inverted...

[tobat7]

Ok, thank you!
Well, I inverted the axis just because the other way round I couldn't see the value on the tag, so I inverted it to make a clearer screenshot :)

[tobat7]

Hello I tried EPSG 32632 and epss 6871 (which is pseudo mercator just like 3857) and it works. Do you think you will manage to solve this? epss 3857 is very common (used by Google Maps and Open Street Map, as far as I know)
thank you.

[nicogodet]

I will try but currently I don't have any time to check this...