BlurView disappears when applying a transform on superview

[simoami]

Hello,
I have a profile coverView which contains an imageView and a blurView (instance of FXBlurView)
When I apply a CATransform3DScale to the coverView, the blur completely disappears. I'm attaching a demo of the issue:

[simoami]

@nicklockwood ^

Any clues why this happens?