World Context node returns inaccurately in PIE/Standalone

When a blueprint function library reaches a "World Context" node, the result returned by the node is invalid / null in Standalone mode. Additionally, the node will occasionally report as invalid in PIE as well.

The behavior has not been seen in a packaged project

Regression:
Yes - the repro listed will print "Context is Valid" in Standalone in 4.16.3 (CL 3561208)

1. Open UE4 Editor
2. Add Blueprint Function Library blueprint
3. Setup BFL blueprint function as shown in attached screenshot
4. Create Blueprint based on Actor
5. In Actor BP, call BFL function on BeginPlay
6. Add instance of Actor BP to the level

Result:
In PIE, "Context is Valid" is printed but in standalone "Context is Invalid" is printed. Additionally, after running standalone, PIE will on rare occasion print "Context is Invalid"

Expected:
World Context is valid in both PIE and Standalone