thread-loader: The loader does not apply config after search up the directory tree for configuration

• Operating System: Windows 10
• Node Version: v14.9.0
• NPM Version: 6.14.8
• webpack Version: 4.44.1
• postcss-loader Version: 4.0.0

Expected Behavior

I have postcss.config.js file in the root of the project, my webpack.config.js is imported from ./webpack/app folder. I expect my postcss configuration to be used/applied correctly.

Actual Behavior

Running webpack ends up with console messages:

You did not set any plugins, parser, or stringifier. Right now, PostCSS does nothing. Pick plugins for your case on https://www.postcss.parts/ and use them in postcss.config.js.

And the postcss.config.js file is actually loaded - I’ve tried to add simple console.log('Im here') to it, and this message appears in my console, as expected. But, apparently, options exported from that file are not correctly sent to postcss.

Code

// webpack.config.js
{
...
module: {
		rules: [
			{
				test: /\.css$/,
				use: [
					MiniCssExtractPlugin.loader,
					{
						loader: 'css-loader',
						options: {
							importLoaders: 1
						}
					},
					{
						loader: 'postcss-loader'
					}
				]
			},
			{
				test: /\.less$/,
				include: APPROOT,
				use: [
					MiniCssExtractPlugin.loader,
					{
						loader: 'css-loader',
						options: {
							importLoaders: 2
						}
					},
					{
						loader: 'postcss-loader'
					},
					{
						loader: 'less-loader'
					}
				]
			}
		]
	}
...
}

// postcss.config.js
module.exports = {
	plugins: [
		'autoprefixer'
	]
};