Faces of cube model change when instantiated?

On the left is a cube dragged into the scene in edit mode, on the right is a cube instantiated at run time. The face orientation changes and I don’t know why. The cube was made in Blender. Any clue? Thank you.

what does the top and bottom texture of the cube look like? perhaps the cube is rotated 90 degrees when instantiated if the rotation of the original mesh or prefab is not set to 0.