Extra Menu Fields not in Graphql default Schema

Problem/Motivation

I added a Field to my Menu and wanted to load it with GraphQL over the Drupal GraphQL module in Version 8.x-3.1. Unfortunately it is not showing up.

Steps to reproduce

• Add Extra Field to Menu
• Add Content to the new Field
• clear cache (so the Schema can be Rebuilded)
• goto /graphql/explorer
• Query for Menu and try to get the added field

Proposed resolution

I Don't know if this is an issue for menu item extra or the GraphQL module.