Encroachment is pretty common especially in older areas.
Surveying is not 100% accurate either, it depends to the proximity of survey marks from earlier surveys.
I’d accept it and give your neighbour a copy of the survey just to let them know. Our neighbour was built 10cm over and our builder put our gutter 5cm over on the other side because he assumed the fence was in the right spot.
2cm really doesn’t cause you any harm.