When you split a track, the point selected when split is included both as the last point in the first part and as the first point in the second part. In some ways that makes sense so that if you display both parts
they join up.
However, this is sometimes not what is required.
Suppose I sail one day from 9:00 to 21:00, anchor
overnight and then sail again from 9:00 to 21:00 next day. Unfortunately, I forgot to stop track recording between the two passages. The track duration shows as 36 hours. But I want to log the two days separately. So I select the first point of the second day and split the track. The second day runs from 9:00 to 21:00 on the second day - 12 hours. Correct.
But the first part has the selected point too and the duration runs from 9:00 on the first day to 9:00 on the second, giving a duration of 24 hours rather than 12 hours.
Only way out is to export the first track as a GPX file and edit out the last point.
I think it should be possible to avoid repeating the point at the split. Perhaps the best option would be to add the ability in the Track properties window to delete a track point. This would also allow cleaning
up a track by topping and tailing it.