Actor Foliage can't be added to Foliage Paint or Single with World Partition maps

Actor Foliage can't be added to Foliage Paint or Single with World Partition maps.

1. Create or open any project
2. Create a new Open World map
3. In the content browser create an Actor Foliage
4. Change to Foliage Mode
5. Choose Paint
6. Drag and drop the Actor Foliage into the '+ Drop Foliage Here'

Expected Result:
The Actor Foliage is added.

Actual Results:
Nothing happens