I made an interior cell starting from a copy of the aaaMarkers cell. While testing it with Dragonborn enabled in my game when I entered the cell there would be 3 live netches embedded in my ceiling at the entance to my cell. I disabled dragonborn and the netches disappeared. It seemed to work ok while testing with my level 60 character. I made a new character and entered the cell for the first time and now when I enter there are 3 mammoths at the same point. What in the world could be causing this? It is an interior cell. There are no enc creatures of any type placed in it.

in the editor, first press "m" in your cell, check if there's any markers etc left over from where you copied that from.

then, best open view -> show/hide tab and enable all markers, and delete all leftovers.

then, look in cell view win if there's a leftover navmesh.

if so, also delete.