GPS distance drift

Hello, when I start the activity and put the Garmin Instinct to the table - after some short time the distance counter shows the higher value then I expected - especially if I compare the same situation with cheaper GPS watch. They are more accurate. See pls attached picture. Changing the GPS system combination (Glonass, Galileo) did not reduce the distance error.
What is wrong? ciq.forums.garmin.com/.../1425859.jpg