Problem to create segments

Hi...i have a problem to create segments from garmin connect on Windows...
i registered an activity with edge 520 plus...
When i go to create a segment for example of 15km of climb, once saved the segment appears shorter, for example 6-8km....the final km of the climb does not come saved...never!!!
I Tried several Times but it is always the sale...part of the segment is not saved!!!!!
Why this happens?????!!!! Help me