Reference to child actor is invalid when compiling the parent blueprint

Reference to child actor is invalid when compiling the parent blueprint. In this example, when compiling blueprint 'A' the print string result will say that "Child Actor ref is INVALID". However, if the child actor 'C' is opened and compiled this will change the result to say that the reference is Valid. Further testing will show that if 'A' is compiled again the reference will once again be invalid (this cycle continues if the blueprints are compiled in an alternating fashion)

1. Download the attached project
2. Open the project
3. Play in editor
4. The print string result will say that "Child Actor ref is Valid"
5. Open blueprint 'A'
6. Compile
7. PIE

Result: The print string result will say that "Child Actor ref is INVALID". However, if the child actor 'C' is opened and compiled this will change the result to say that the reference is Valid
Expected: The results would be consistent after compiling the blueprints (as no actual changes have been made)