Hello, I guess this could be related to #27.
I am using postcss-critical-css with Webpack 4 (Windows 10) and I am facing the following issue: when importing in the same JS entrypoint several scss partials containing critical at-rules pointing to the same output file, seems like the generated css carries just the contents from one of the sources (usually the one from the last saved source file). Each at-rule overwrites the previous. Sometimes partial overwrites could happen as well, generating syntax errors in the output.
This happens for static scss imports and for dynamic imports of JS files carrying scss imports, as well.
See this repo for further explanation.
Thanks