the most common reasons that caused the robot to "Cross Outside":
1.
Was the perimeter wire installed in an area that is too sloppy?
2.
Did it happen under wet conditions?
3
Is there a difference in height between the grass and the edge of the garden?
4
Is the perimeter wire installed too close to the edge?
5.
The wire is not set at 45 degrees at the corner or it is set at 45 degrees but at a very short distance from the corner.