Imported model, child object issues

So I made a Blender model "1x1" with multiple objects in it. Everything inside imports and shows up fine, but if I try to drag any children of this imported model prefab into scene view, it will just place down the entire 1x1 parent, but simply change its name to whatever child was selected.

For example, if I want to drag out "Door", it just creates the whole 1x1 parent as a prefab, but changes the name to "Door".

Any insights on how to deal with imported models like this?

Having to pull the base model prefab apart and create 20+ new prefabs just to have access to each seems overkill.

 

I would drag all into the scene and then create prefab variants for the objects, so you can change them independently of your imported object , but you still have the reference to the imported object if something changes there.
Else, export each part as its own file.