Scrolling Frame Automatic Canvas Size

Well just want to know, why when I put a frame inside Scrolling Frame and Inside the frame I put List of Frames, the Automatic Canvas Size of the Scrolling Frame doesn’t work? But if I put list of frames directly under Scrolling Frame the Automatic Canvas Size is working? How does Automatic Canvas Size really work?

Example-1 (Work)
Ex-1

But if I make like this, it doesn’t work, the Automatic Canvas Size
Ex-2

Can you screenshot the UIGridLayout’s properties?