I just tried opening a past (recorded on a 735XT a firmware prior to, I think 7.3 - most likely when the 735XT was still writing Fitv1 files for multisport events) multisport event (either a brick training or a triathlon) and in both cases the running part of the multisport event is broken (GPS map not visible). However at that time the file was correctly parsed by GC and it has been read by Strava and TrainingPeaks.
I did attach the respective FIT file exported from GC.
It appears that GC tries to parse the FITv1 file as a FITv2 file and somehow fails.
Any ideas on how to fix things?