I use Blender and the Send2UE plugin to get my models into Unreal. A lot of these models have the same material with the same name. But when Unreal imports them it creates a new material when that material already exists in the parent folder.
I imported a fbx in Unreal and set it to Do Not Create Material and All Assets for the search location. This uses the material in the parent directory and doesn’t create a duplicate. I clicked Import All in the fbx importer to apply this to all future imports, but it still creates duplicates when using Blender.