How to fix a missing segment achievement:
For a missing segment achievement, first try the Refresh My Achievements tool, located under the wrench icon on the activity page when accessed on the Strava website. If your fastest time isn't showing correctly on the segment leaderboard, review the possibilities outlined here.
How to fix segments that are missing from your activity:
If you're missing a segment entirely from an activity, scroll down below the list of matched segments to the option "Don't see the segment you're looking for?". Search for the missing segment using the Potential Segment Match Analysis Tool then reach out to us for further assistance.
Missing or Inaccurate run achievements for Best Effort distances:
For achievements on estimated Best Efforts for Running, Strava requires good quality GPS recording throughout the effort. If there are missing points, errant points or other false accelerations then part of the activity may not be eligible for a Best Effort.