Physics object from a streamed level does not interact with other physics objects in persistent level.
1. Create a persistent level and a streaming level.
2. Add any Blueprint to the streaming level. The Blueprint must be set to Movable, but can otherwise just be empty.
3. In the world outline for the streaming level, attach a StaticMeshComponent to the BP. Set the mesh to a standard cube.
4. Make sure the level is not loaded in the editor and press play. (If the level is initially loaded in before pressing play the problem does not occur.)
5. During play the collision of the attached component is ignored by characters, physics and traces.
The BP and the attached StaticMeshComponent both have PhysicsSimulated set to false.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-109543 in the post.