No respawning in internal areas

[Jonnan001]

Enemies in the wasteland itself (and containers) respawn as expected, however internal areas never seem to repopulate. I’m unsure about containers - I find just enough containers with items a month later to be unsure if I missed some on the first pass or they respawned.

But I went out to point lookout, completed it, and returned, still no respawns?

[Risewild]

That's how Fallout 3 is.
There's no creature respawning in interiors.

[Jonnan001]

Have to admit I had evidently forgotten that, but googling confirms Bethesda and one other place respawn but nothing else.

Well fine raiders, just stay dead, see if I care. I didn’t want to waste a bullet on you anyway.

[Risewild]

It's not really a solution, but if you're missing having some more enemies to deal with, you could try a "more spawns" mod.
FiftyTifty has a 2x and 3x more spawns mod:
viewtopic.php?f=55&t=6678
It can be a bit tricky to make it work, but there's useful instructions here:
viewtopic.php?f=55&t=6678&p=70613

While it doesn't make enemies respawn in interiors, it does double or triple the number of enemies respawned. So way more things to kill... or run away from, I guess.