This is on a 3200 proc gen custom map.

P15 is displayed on the HUD, but player location on map is actually in P16


I'll take a look on the code myself when time allows but just throwing this out here for awareness for now.

there is an option in the config.json file called mapGridYOffset. Just set it to 1 or -1 and test it if this will fix for your map.

This is a hacky solution I came up with until I have time to properly rewrite the grid code to adjust correctly to any map size