It seems that Chrome doesn\'t handle justify-content: space-around correctly when the content overflows the flex container, and the container is not set up to a
Since the container is limited in width and you want overflowing flex items to be accessed via horizontal scrolling, why use justify-content: space-around?
Try justify-content: flex-start:
Revised Codepen
To understand why overflowing flex items may be inaccessible via scroll, see this answer.
If you're interested in a Javascript workaround for the original code, see this post: