ScrollingFrames do not adhere to size constraints applied by a UISizeConstraint when using AutomaticSize and AutomaticCanvasSize, and continue to grow beyond the maximum specified size.
ScrollingFrameAutomaticSizeRepro.rbxm (8.4 KB)
Expected behavior
I would expect the ScrollingFrame to grow as big as the UISizeConstraint allows, and when it hits the maximum size, the ScrollingFrame’s canvas will continue to grow while the bounds of the ScrollingFrame itself remain at the specified maximum size.
In the case where you would expect both the canvas size and the frame size to not exceed the specified maximum size, you would actually want to be using a Frame, since there would be no need for a scrolling mechanism in this scenario.