EDIT: nevermind, I have this issue also in 4.0 it seems. Probably some problem on my side.
Although I still can't add any FBX models from the resources section. The only way I can add FBX models is to drag a file from Finder directly into the scene hierarchy ("Objects"), then it imports and is visible in the scene. Once deleted from the scene I can't add the same already imported file from Resources.
I just upgraded to 4.1 and can't add imported FBX (nor GLTF) objects to the scene any longer.
I drag them from resources to the scene and nothing happens.
Also in a brand new project, with models that worked in 4.0. What is going on? Can I get 4.0 somewhere so my work is not blocked?