FlushLevelStreaming() Failure

After calling FlushLevelStreaming on a world that houses 212 SubLevels and inspecting the sublevels SoftObjPointers, 2/3 are STALE or nullptr. Why would that be happening?

Is there a cap on how many sublevels (memory capacity) that FlushLevels can handle?

During the load of the 212 SubLevels there are errors loading certain static meshes (due to missing textures) but it shouldn’t prevent the levels from loading.