Related: Support - TailwindCSS - HTML Template change not triggering CSS/PostCSS rebuild
The problem revolves around the fact that postcss does not get invoked by Hugo on “partial” rebuilds.
The hugo builder will handle different scenarios accordingly, in an attempt to prevent unnecessary rebuilds.
Full Rebuilds:
On Config file Change
On FSNotify events > 50
etc…
See: hugo/commands/hugobuilder.go at 1a53a8c2f5af4c1700ca98133db49a1126fd74ef · gohugoio/hugo · GitHub
I still do not understand how this seemingly affects only a minority of the users, indeed strange.