i managed to figure it out how to export from blender 2.8 to cartographer. it is an issue with blender 2.8 due to how it imports, this issue doesnt happen for 2.7.
To use blender 2.8 you need to do these steps.
1. import map object
2. go to edit mode and select all, then separate by material
3. rename each isolated material to only the name of their material, as well as the submenu and the material itself. The materials are the 10 options (plain, bridge, desert, forest, mountain, river, snow, steppe, steppe_forest, water)
4. for each material in their "surface" section, disable "Use Nodes"