Horizontal scrollbar in stories list incorrectly sized

When expanding and then shrinking the main widget horizontally, the contents of the list frame expand horizontally but do not shrink, causing the canvas size of the scrolling frame containing the stories items to be larger than it should. This makes the scrollbar appear at the wrong time / at the wrong size.

https://user-images.githubusercontent.com/25118482/186985224-201b1b46-8203-4365-8c6e-06d86bd4f86a.mp4