The UStaticMeshComponent.PreviousLODLevel variable always returns 0 no matter what the last LOD actually was.
This also occurred in 4.16
Steps to Reproduce
Download the attached project, generate project files and then compile.
Open the project and place the Output log in a way so that you can see it while you play
Move the camera closer and further from the cube in the middle to make it swap between LODs
Result: The output from PreviousLODLevel always returns 0
Expected: The output from PreviousLODLevel changes each time the LOD changes.