Unloading sublevels causes slight freeze on Mac

Unloading sublevels causes slight freeze on Mac. It is noticable during PIE. This does not occur on Windows OS.

1. Open editor (any project)
2. Create new level with 2 sublevels, ensure there is lighting in the persistent level (default level works for this test)
3. In each sublevel, add some type of surface/object, place these on either side of the main level
4. Add trigger volume to level blueprint
5. Create level blueprint in attached image
6. Compile
7. Press PIE
8. Look towards each level as it is loaded
9. Move character into trigger volume

Results

Freezing/hitching while level is unloaded

Expected

Level unloaded, no noticable hitching/freezing occurs