Wrong borderline coordinates on higher zoom level Maps

I made different zoom levels from the same map.
I was located at top-left boundary of the first map coordinates.
and I saw different maps at the point where the player markers are displayed.
But, those level-2 or more maps displayed player markers are shrunk.

The difference in each coordinates are 2-16 blocks.
If someone discriminates the boundary in the form of a player marker and creates a map of the new neighbor area with that, it will fail.