This is not a bug from GpxPod. If you look inside the converted .gpx file. There are two tracks with the same coordinates but different altitude values. I guess it is the way GpsBabel converts IGC to GPX. First track's name is PRESALTTRK and second's is GNSSALTTRK. It means to me that the device you use to record the track writes two values for altitude measure : the one from the barometer (pres for pressure) and the one from the GPS chip (GNSS for Global Navigation Satellite System). Then GpsBabel decides to produce two tracks in the GPX.
Thanks! So would it be possible to add the option to convert just the selected track? Gpsbabel seems to work with just PRESALTTRK or GNSSALTTRK which could be filtered by eg. -x track,name=GNSSALTTRK
It could be filtered but maybe some people would like to see PRESALTTRK instead of GNSSALTTRK. I think i prefer letting GpsBabel produce a file with the two tracks.
From now on, there is an option to choose between both, gnss and pressure elevation tracks. It only applies to converted IGC tracks. To apply this change to your already converted track, just delete the 01-1806.gpx file (from GpxPod or Files app). It will convert it again and apply selected filter.
Does it work on your side ? Don't forget to empty your browser cache after updating GpxPod files to be sure you load the correct Javascript code.