I'm doing a mod that has a new worldspace and then new interiors in the 'Interiors' world space. The new worldspace and the new interiors both have dwemer spiders.

If I coc to the worldspace, the spiders are there.
If I coc to the interior, the spiders are there.

If I coc to the worldspace and then enter the interior, the spiders outside spawn but the ones inside won't spawn.
If I coc to the interior and the leave to the worldspace, the spiders inside and then outside both spawn.

Anybody have any clue what would make dwemer spiders only spawn if you coc directly to their cell?

Note, things I've tried:
1) Starting a new game and getting into the worldspace and then the interior still results in spiders outside spawining but not inside... so it's not a bug with COC.
2) Navmeshes in both areas appear to work when I coc directly. The exterior spiders will follow through all the doors and run around. The interior spiders (after cocing directly) won't follow me out, and then are gone when i go back in.
3) I've tried both leveled and normal Enc spiders and centurions inside. They also don't appear to have AI packages or anything.