Foliage mode instances not rendered until mouse up

New foliage is not visible when applying the paint tool and only shows up after the painting ends.

1. Create a new Level and a Static Mesh Foliage Asset (use EditorCube as Static Mesh as shown in the image)
2. Open the level and add a plane to the scene (Add->Shapes->Plane)
3. Enter Foliage Mode and Paint the foliage asset created in 1: you won't see anything until you release the left mouse button