I've recently done two swimruns for about 3-3.5 hours with the watch (Garmin FR 965 with 19.18 software) set to Swimrun as activity and Auto Sport Change on. There were ten runs and nine swims.
Both times the watch shows a much longer total time, than is possible (3 hours and 40 min for the swimrun that was 2 hours and 58 minutes) so there is something wrong with the activity and it won't sync to the app.
I mounted the watch on my computer and copied the FIT file and ran it through the GOTOES tool (since I'm on a Mac I can't use the Fit File Repair Tool) and it fixed the FIT file with the correct time and I was able to upload it to Garmin Connect web. But the multisport parts was no longer individually shown as a normal multisport activity would, but instead it's just one activity with splits.
So I have two questions:
1) Is there a known bug with multisport and Auto Sport Change that causes corrupt files?
2) Is the Fit File Repair Tool better at preserving the multisport correctly?
I did erase all my previous activities from the watch before the second swimrun.