I remember running into this a few times before, years ago, but I just ran into it again, recently and today, and it's been driving me nuts.

There's a bunch of props which are supposedly suitable for prop_static (as in, the model browser lists them as such), that apparently aren't. When I place them in the world as prop_static, they straight up don't appear in the game. Neither the compile log nor the in-game console show any errors, they prop simply doesn't show up.

Affected models are, among others:
  • models/props_wasteland/controlroom_filecabinet002a.mdl
  • models/props_c17/lockers001a.mdl
  • models/props_junk/trashdumpster01a.mdl
  • models/props_wasteland/kitchen_shelf001a.mdl
So far, all models I've seen this happen with are models that are listed as physics and static props in the model browser, and they're all official Valve models shipped with and used in the games.

For each of them, I have to use prop_physics with all the flags that make it as static as possible, or prop_dynamic_override, both of which are computationally less efficient than prop_static and just irritating workarounds. Furthermore, the only thing I've found about this on the web is this Reddit post, which does suggest a solution, but a complicated one (using a different compiler from a different game), and which I'm not sure is even applicable, considering EP2 already runs the Source 2013 branch of the engine.

If anyone has an easier workaround, or can tell me why this is happening in the first place, I'd be very grateful.