Bug

The minifier turns flex: none into flex: 0 0. These are slightly different as none refers to flex: 0 0 auto where flex-basis: auto, and flex: 0 0 is interpreted as flex-basis: 0. This causes some issues with my website, namely bulma columns relies on flex: none to allow the width of each column to be set by the width property. If I minify

MDN shows that when both the flex-basis and width are set, then the flex-basis takes priority. Thus the minification should not perform this transformation just to save one character.

Fix

Turns out I am running Hugo v0.69. The new version of Hugo v0.70 has an updated minifier that does not do this, and this is what I publish my website with. In order to view content locally all I needed to do was update Hugo.