Connection lost azure webpubsub socketio / nodejs

After some inactivity (e.g. computer goes into sleep modus) the connection to azure socket io hub gets lost. My express server functions normally so http requests are served but clients can't connect to the hub anymore as they get the message there is no backend service connected to the hub.
How can I prevent this loss of connection or at least automatically reconnect when it happens? I tried to listen to disconnect events but they are not triggered when the connection gets lost.

const httpServer = createServer(app)
export let io
async function main() {
  const socketIOAzure = require('socket.io')
  io = await socketIOAzure(httpServer).useAzureSocketIO({ hub, connectionString })
  io.httpServer.listen(port, () => log({ level: 'info', message: `Server is running on port ${port}` }))
}
main()