Trobleshooting computed field with Drupal 8 (Drupal core 8.3.2

• 8.x-1.0-alpha1 does not work with Drupal core 8.3.2 (you'll get unexpected errors) >> Choose 8.x-2.x-dev
• Computed fields don't display on content types which existed prior the module is installed >> Create a new content type and everything works smoothly

Important: The field only updates when the node is saved (Cron, clear cache and similar not enough)