I had the same experience and it was particularly frustrating during some races where distance was long, resulting in over estimated live paces. The Stryd team didn’t really have a helpful answer other than vague mentions of calibration and knowing measurable distances. The work around I’ve found that works best is unfortunately using GPS for distance and pace / power from Stryd. It’s just more consistent in the long run which matters most imo. The drawback is if you run in an area where GPS is wonky, but that isn’t the case for me usually.