Duplicate Static Meshes Don't Seem To Be Auto-Instancing?

When I change my View Mode to Nanite Visualization → Primitives, I get the following:

If you can tell what you’re looking at (lol), this is a room. I used a single “modular” square mesh, duplicated a bunch of times around the world as Static Mesh Actors to fill out the ceiling, floor, and most of the walls.

Now, I didn’t manually set up any mesh instancing, but it was my understanding that Unreal/Nanite do a lot of dynamic/auto instancing stuff, right? So I guess I expected that most of the room here would be the same color.

Am I misinterpreting these results, or is it something I’m doing wrong that would prevent these from getting the instancing they deserve?

I’m not sure how materials effect this, but a few of the walls are using a different material instance. But for sure the ceiling meshes are using the same material, and MOST of the walls are, too.


Note: Oh, uh, you might notice the screenshot shows me in “Instances” view mode. But rest assured, it looks the same way in “Primitives” view.