Isometric Tilemap layer problem help

[Bong Dark]

sorry as my poor english

I'm making 2D isometric tilemap on Unity by using the 2D Toolkit.
And I wanna spread some specific object which has a collision.
So I linked a object and a prefab on data tab of tilemap editor, clicked the commit button, and the layer has totally broken.

Like this orange tiles (prefab I assigned)


I think the sprite offset and layer priority of prefab is the main cause as it's overwriting tile properties and offsets I've adjusted on the tilemap editor.
Can anyone solve this problem? I've tried to search similar questions on this forum and found several solutions but unfortunately couldn't help me.

Thanks for your time and please help me!!