STR:

• node@v14.15.3
• Install webpack-dev-servernpm install --save-dev webpack webpack-dev-server webpack-cli @webpack-cli/serve
• Run webpack serve --mode development --allowed-hosts all

ER: allowedHosts: 'all'
AR: allowedHosts: ['all']

This lead to ignoring this option by Server

And visual error Invalid Host header

package.json

{ "main": "src/jindex.js", "scripts": { "test": "webpack serve --mode development --allowed-hosts all" }, "devDependencies": { "@webpack-cli/serve": "^1.5.2", "webpack": "^5.51.1", "webpack-cli": "^4.8.0", "webpack-dev-server": "^4.0.0" } }