InteriorBlend file includes all the objects visible on the image.
If you plan to use obj. file, you will have to link textures since those swich/ flip or in fbx straches. That's normal, obj and fbx seems to have issues packing textures or exporting transparent shader.
Render engine : Cycles Created in Blender ver. 3.0.1 Vertices : 156,478 Faces : 156,248