Troubleshooting
Kart's stick continuously to their current geographical object. Transferring to new geography requires the beginning of a new object parallel to the old object or an aerial maneuver (ex. a jump).
Normally due to a triangle being too long. Try splitting the longest triangles into multiple triangles.
In blender press CTRL+A and click Apply Transformations. Experiment checking Apply Transform in export settings.
In-game example:
In-editor example:
Observe that two separate objects are overlapping each other. Solve this by adding more vertices to the objects and connecting the vertices together:
