CSS output inconsistency between builds

[mrmntte]

The problem npm run build doesn't include all/some classes in the final css file. Usually only the first build (without .next/ cache) is generated correctly, but it's inconsistent. I'm not sure if this also makes it happen randomly with npm run dev when navigating between routes.

all classes are missing:

some:

How to reproduce run multiple times npm run build && npm run start https://stackblitz.com/edit/github-kh7iw4?file=app%2Flayout.tsx

Expected behavior

[steida]

I also have to occasionally remove .next dir to refresh styles.

[nmn]

This is a known issue which is why the NextJS example in the repo does this:

"clean": "rimraf .next",
"predev": "npm run clean",
"prebuild": "npm run clean",

I've already reached out to the NextJS team for help. In the meantime, I'll fix the Stackblitz example.