Construction script not updating HISM array count

Construction script not updating HISM array count, even when new elements are adding inside of the level.

Regression:
Issue occurs in 4.15.1 of the binary build

Using the same repro steps provided by the user in 4.14.3 and 4.13.2 could not reproduce the issue because new array elements could not be added from the actor in the level

1. Open a new project (No template or starter content)
2. Create a new Actor class blueprint > Name it "Actor_BP" > Open Actor_BP
3. add a Hierarchical Instanced Static Mesh Component
4. In the Details panel > Static Mesh > View options> check show engine content and set the static mesh to a cube
5. Add 2 array elements under the Instances section
6. In the Construction script add a Reference to the HISM and from it get the get instance count node
7. Add a print string and connect it to the construction script purple node and connect the Instance count output pin into the print string
8. Add Actor_BP to the level and move it around (Expected result)
9. select Actor_BP in the level and find the HISM component in the details panel and select it
10. Find the Instances option and add more array elements to the component
11. Move the blueprint around again

Result: The print string will not update to the new instance count
Expected result: The print string updates to the new count