[2840] DevTools failed to parse SourceMap when having custom routes

I need to have routes like this: a fixed/hardcoded segment followed by any number of free-form segments (like: /posts-from/2018/10/05).

So I

• generated a project based on nuxt-community/starter-template
• installed stylus and added a .styl file
• added a custom route (via example) nuxt.config.js router: { extendRoutes (routes, resolve) { routes.push({ name: 'custom', path: '/custom/*', component: resolve(__dirname, 'pages/index.vue') }) } }
• all my changes are here

Now on dev mode (yarn run dev) I can open /custom/1/2/3 - which is what I want. But, when I open that page, Chrome logs: DevTools failed to parse SourceMap: http://localhost:3000/custom/1/2/assets/style/app.css.map

Am I doing something wrong or there is an issue with Nuxt? Thanks

(Also, but this seems to be a different issue, when I open the root page (/), the server logs: { statusCode: 404, path: '/assets/style/app.css.map', message: 'This page could not be found' }.)