Deleting platforms on one level deleted it on different level too?

Unity Engine
1

So I used the Unity Standard asset thing, the one that comes with those pre-made shapes (idk what else to call it). But they are called platforms. And deleting some on one level also deleted some on another level. Bug?

I didn’t unpack the prefab before doing it. Is that why?

Though I never had that problem (so far) with my own images I drew and imported into the project.

2

You probably deleted the prefab in your project window, instead of hierarchy window.

If you delete a prefab asset, then all objects that used it to build an instance also can appear to be deleted.