react-helmet-async: Helmet tag not being updated in production with server rendering

HI @staylor! While implementing this library with server rendering, I am noticing that while the updated tags show up in the server-rendered code in development, they do not do show up in production.

Here is my code on the server side. Specifically helmetContext.helmet.meta.toString shows up as empty in production while it works perfectly fine in development. I’m on React 16.5.2, Webpack 4.16 and Node 10.

// Holds Helmet state specific to each request
const helmetContext = {}

// Declare our React application.
const app = (
  <AsyncComponentProvider asyncContext = { asyncComponentsContext }>
    <JobProvider jobContext = { jobContext }>
      <StaticRouter location = { request.url } context = { reactRouterContext }>
        <HelmetProvider context = { helmetContext } >
          <Provider store = { store }>
            <CookiesProvider cookies = { request.universalCookies }>
              <UserAgentProvider ua = {request.headers["user-agent"]} >
                  <IntlProvider
                    locale		= { locale }
                    messages	= { messages }
                    initialNow	= { Date.now() }
                    textComponent = { Fragment }
                  >
                    <Route component = { App } />
                  </IntlProvider>
              </UserAgentProvider>
            </CookiesProvider>
          </Provider>
        </HelmetProvider>
      </StaticRouter>
    </JobProvider>
  </AsyncComponentProvider>
)

// ℹ️ First we bootstrap our app to ensure the async components/data are resolved
await asyncBootstrapper( app )

const jsx = sheet.collectStyles( app )
const stream = sheet.interleaveWithNodeStream(
  renderToNodeStream( jsx ),
)

// Resolve the assets (js/css) for the client bundle's entry chunk.
const clientEntryAssets = getClientBundleEntryAssets()

const { helmet } = helmetContext

/*
* all of the things in the params below are included in the header
* can add htmlAttributes & bodyAttributes from Helmet if needed
*/
const paramsForHeader = {
  titleTag:	helmet.title.toString(),
  metaTags:	helmet.meta.toString(),
  linkTags:	helmet.link.toString(),
  cssBundle:	clientEntryAssets && clientEntryAssets.css,
  nonce,
}

console.log( "metaTags toString:", helmet.meta.toString())  // nothing
console.log( "metaTags toComponent", helmet.meta.toComponent()) // nothing either

/*
* all of the things in the params below are included in the footer
*/
const paramsForFooter = {
  storeState:	store.getState(),
  routerState: reactRouterContext,
  jobsState:	jobContext.getState(),
  asyncComponentsState:	asyncComponentsContext.getState(),
  jsBundle:		clientEntryAssets.js,
  clientConfig,
  polyfillPath,
  nonce,
}

switch ( reactRouterContext.status ) {
  case 301:
  case 302:
  // ...
      break

  case 404:
  // ...
      break

  default:
      // Otherwise everything is all good and we send a 200 OK status.
      response.status( 200 )
      response.type( "html" )
      response.setHeader( "Cache-Control", "no-cache" )
      response.write( Head( paramsForHeader ))
      stream.pipe( response, { end: false })
      stream.on( "end", () => response.end( Footer( paramsForFooter )))
}

Any ideas what might be going on?