In brief
flex-shrink controls shrinking when space is insufficient. Distribution also considers base sizes, so equal factors do not necessarily remove equal numbers of pixels.
Useful to know
flex-shrink controls shrinking when space is insufficient. Distribution also considers base sizes, so equal factors do not necessarily remove equal numbers of pixels. [1]
For a small icon, flex-shrink: 0 can preserve size while the text area adapts. Check a long label rather than disabling shrinking on every item.
Sources
For further detail and to check the information: