I am working with an .fbx model. I place multiple objects within new collections I create, and export the .fbx to save the model. But when I reopen the model (import .fbx) all of the collections I previously added are gone. Instead, all objects are placed within the default collection, "collections"; and if I delete the default collection "collections", then all objects are placed within "scene collections." It's a large model with thousands of objects and this is preventing me from organising my work!