Map showing gps spike at the beginning of the run

In last two runs, I am seeing a behavior where the GPS at the beginning of the run is not working correctly.

This is happening even though I am waiting for the green GPS signal before starting to run.

Yysterday I ran at the park. The starting location should have been the same as the ending one.

The laps results are correct, but the map shows like I've started my run at a different location.

during the run, I stopped once for drinking for a few seconds and resumed right after from the same spot.

Any ideas ? Is my watch faulted

I have Garmin Forerunner 255 Music