Using Bake Material Position Offset Into Collision causes landscape to have no collision

Creating a material with World Position Offset and enabling "Bake Material Position Offset Into Collision" causes the landscape to have no collision. Disabling this feature causes collision to come back on the landscape.

1. Sync to CL - 2826455 in //UE4/Dev-Mobile
2. Create a new level and create a new landscape
3. Create a material (refer to image of material)
4. Apply new material to landscape and set weight blend to all layers
5. Paint entire landscape with red layer first
6. Paint into landscape with the green layer.
7. Green paint should raise landscape because of WPO
8. PIE
9. Walk through the height of the green layer because it isn't baked into collision
10. Shift +1 to go from landscape mode to place mode
    #Select Landscape
11. Under Collision, "Show Advanced"
12. Check the box for "Bake Material Offset Into Collision"
13. PIE

Result: Player falls through landscape.