My current job is making a giant pine tree in the map. The problem is in the map, as well as in the mesh preview the small branches on the tree shifting its position downward towards the ground as the camera zooming away from the tree, starting from a certain distance. The tree has no lod. but in mesh preview I can switch the lod to lod0, which solves problem in the mesh preview but not in the map.
the engine probably created a auto lod. you can open the mesh and check for the auto setting . another thing to try is placing the mesh in a level then in the details panel under the rendering section play around with the force lod setting.