Our team is working with FBX files for our model importing and we have been having issues where an updated FBX is not showing new textures when brought into Unity. For example, there is an environment with many separate pieces that have their own textures that appear fine when bringing it in the first time. When someone makes changes and saves out a new FBX the textures that have been modified are fine, but any textures that have been added or reassigned do not show up at all in the editor. I can manually set these missing textures, but this is far from ideal.
Basically, what is the proper way to update an FBX with all of the changes intact?