Hi Alexander,
I moved to new version 26.5 and here my results:
Please see:
Test data(input/output/QGIS)
5372-Gml Gpx.zip (64.9 KB)
Thanks,...Bug 5372: Gml to Gpx- Conversion succeeded, output in QGIS -...(gml3.gml) is incorrect for conversion. No root element declaration...