In Next.js 10.0.3 version we have to use Material-Stylesheets for SSR in _document.js and appropriate style loaders in next.config.js . Im using Material-ui and i faced the same issue and added the code below...For me it resolved the issue. Hope this will resolve your issue.
next.config.js
module.exports = withImages({
target: '//your target',
webpack: function (config, { webpack }) {
config.module.rules.push({
test: /\.(eot|svg|gif|md)$/,
loaders: ['style-loader', 'css-loader', 'less-loader']
})
return config
},
})
_document.js
import React from 'react'
import NextDocument from 'next/document'
import { ServerStyleSheet as StyledComponentSheets } from 'styled-components'
import { ServerStyleSheets as MaterialUiServerStyleSheets } from '@material-
ui/styles'
export default class Document extends NextDocument {
static async getInitialProps(ctx) {
const styledComponentSheet = new StyledComponentSheets()
const materialUiSheets = new MaterialUiServerStyleSheets()
const originalRenderPage = ctx.renderPage
try {
ctx.renderPage = () =>
originalRenderPage({
enhanceApp: App => props =>
styledComponentSheet.collectStyles(
materialUiSheets.collect(<App {...props} />),
),
})
const initialProps = await NextDocument.getInitialProps(ctx)
return {
...initialProps,
styles: [
<React.Fragment key="styles">
{initialProps.styles}
{materialUiSheets.getStyleElement()}
{styledComponentSheet.getStyleElement()}
</React.Fragment>,
],
}
} finally {
styledComponentSheet.seal()
}
}
}