Confusing, GMT v0.38.0 https://github.com/GenericMappingTools/GMT.jl.git#master should be the master version. And with that it works for me. Note that your data is geographic so if you plot it linearly you see the split you showed before. I made a couple of attempts and I get.
I will tag a new version (will be 0.38.1). Keep and eye on the GMT.jl repo (maybe a 1/2 till it gets done).
julia> D = gdalread("R1v1.gpx");
Warning 1: The output driver does not natively support DateTime type for field time. Misconversion can happen. -mapFieldType can be used to control field type conversion.
Warning 6: Field time create as date field, though DateTime requested.
Warning 6: Normalized/laundered field name: 'geoidheight' to 'geoidheigh'
Warning 6: Normalized/laundered field name: 'ageofdgpsdata' to 'ageofdgpsd'
Warning 6: Normalized/laundered field name: 'route_point_id' to 'route_poin'
Warning 1: The output driver does not natively support DateTime type for field time. Misconversion can happen. -mapFieldType can be used to control field type conversion.
Warning 6: Field time create as date field, though DateTime requested.
Warning 6: Normalized/laundered field name: 'geoidheight' to 'geoidheigh'
Warning 6: Normalized/laundered field name: 'ageofdgpsdata' to 'ageofdgpsd'
Warning 6: Normalized/laundered field name: 'track_seg_id' to 'track_seg_'
Warning 6: Normalized/laundered field name: 'track_seg_point_id' to 'track_se_1'
Warning 1: The output driver does not natively support DateTime type for field time. Misconversion can happen. -mapFieldType can be used to control field type conversion.
Warning 6: Field time create as date field, though DateTime requested.
Warning 6: Normalized/laundered field name: 'geoidheight' to 'geoidheigh'
Warning 6: Normalized/laundered field name: 'ageofdgpsdata' to 'ageofdgpsd'
julia> imshow(D, proj=:eqc, region=(135,240,34,57), par=(MAP_FRAME_TYPE="plain",))
