Incorrect GPS starting point causing shifted route

Hi everyone,

I bought a Garmin Forerunner 265 last December to replace the running app on my smartphone.

I always run the same route. The distance is usually very stable, and the GPS track is normally accurate and matches the real path. If needed, my runs can be checked on my Strava account.

This morning, for the first time, the starting GPS position was wrong. It seems the watch detected an incorrect starting point, and then shifted the whole route to match it. Because of this, the activity shows me running through streets I did not take.

As a result, the distance and the time are not accurate for this run.

I have attached two images :

  • a first one, from a normal run on this route
  • a second one, from this morning’s problematic run

I’m looking for help to understand why this happened and how I can avoid it in the future.

Thanks a lot for your help.