Huge game window when launching onto Safari 9.1.2

The game window in the Safari browser expands to a huge size along the Y axis.

We do not see this issue on Safari version 10.

The game window expands for about 5 minutes before the game is playable.
The game window takes up a lot of processing power which causes the mouse to skip around.
The user is unable to use the web inspector.

1. Open UE4Editor.app
2. Create a new Vehicle BP project
3. Select the drop down menu to the right of the Launch button
4. Select Safari in the Launch On drop down menu

RESULT:
The Safari browser opens and tries to load the Vehicle BP game. The game's window in the browser remains black and infinitely expands.