Duplicating a folder in World Oultiner only duplicates the first actor in the folder

Duplicating a folder in World Oultiner only duplicates the first actor in the folder

Regression (no) issue (does) occur in 4.12.5

1. Open Editor (any project)
2. Modes>Placement>Basic> Add one cube and one sphere to level
3. RMB on "Minimal_Default(Editor)" in World Outliner
4. Create new folder
5. Add cube and sphere to new folder
6. Copy folder
7. Paste folder in outliner

Results

Cube is duplicated, sphere is not. No folder is created in World Outliner Hierarchy.