So, I have a hex TileMap with flattop, and I am using local_to_map(get_global_mouse_coord) in order to get the tile coords.

The issue I am finding is that diagonally the Y coord goes (0,0),(1,0),(2,1),(3,1),(4,2), ect...

This is difficult because the increase isn't consistent and I am unsure how/if I can fix this, it is making many of my calculations very difficult. Any suggestions on why this is/how I might be able to fix it?

Solved my own issue, with the TileSet set as stacked or stacked offset it calculated in a zigzag pattern left to right for the Y axis, rather than by rows and columns, I changed it to stairs down and that fixed my issue!