loadurdf with large .obj file, only the first two objects are imported.

[vikishaw2]

I want to import five mesh objects(.obj), each about 50MB, with the loadURDF function. However, only the first two objects are imported, regardless of the order of these objects. In addition, KukaDiverseObjectEnv could import many mesh objects(.obj) with the loadURDF function. I found the mesh file is about 20KB in this environment. Does the size of mesh object affect the result? How could I import multiple mesh objects of large size?