Variables cast from the Construction Script do not update in AnimBP AnimGraph

Variables cast from the Construction Script do not update in AnimBP AnimGraph

The attached project has the head scale value cast from the Construction Script to a value in the AnimBP that scales the head via Transform Bone.

1. Open the attached project in 4.11
2. Select the CharacterBP in the level
3. Search for "Head Scale" in the details
4. Scrub any of the values

Result: Head scales accordingly

5. Convert the project to 4.12
6. Repeat steps 2-4

Result: Nothing happens to the head
Expected: Head scales like it did in 4.11