I hiked around a lake, and had a swim in the middle. I recorded it as one activity. Once uploaded, I wanted to edit it to save as two activities - one complete Hike, and one Swim. In order to do this I
- used the activity split tool (into 3)
- download GPX for activities 1 & 3
- did some GPX file manipulation to get a combined Hike GPX file (using original activities 1 & 3)
- deleted the 2 original Hike pieces (i.e. original activities 1 & 3)
- cropped the original Swim piece (i.e. original activity 2)
- attempted to upload the new Hike (i.e. merged original activities 1 & 3)
However, it wasn't allowed. Your checking of the GPX file I was uploading said it was identical to the original Swim activity that had been uploaded. This is despite the fact that due to cropping, there was no overlap between the 2 files. This suggests that despite the splitting and the cropping, the "identical check" uses pre-split and/or pre-crop information. Which is obviously a bug (that presumably has a simple fix).
I did manage to do what I needed to, by
- Downloading the Swim (original activity 2)
- Deleting the Swim
- Uploading both GPX files (Swim (2), and combined Hike (1 & 3))