How do mandatory fields work in related and nested content - testing

1. Adding these items which contain mandatory fields in nested content.

What happens to the other items if one of them does not have the mandatory field filled in on save/publish?

Biography - content You know that it hasn't saved because the 'optional name' is not filled in in the CMS

facebook post- content
sketchfab- content
tweet- content

internal link - added in using 'Also of Interest' in Related Content You know that it hasn't saved because it just says #loading'
list entry link - added in using 'Also of Interest' You know that it hasn't saved because it just says 'Item n' (where n = 2 in this case
related publications -- related content. You know that it hasn't saved because the 'optional name' is not filled in in the CMS
Sponsor - related content. You know that it hasn't saved because the 'optional name' is not filled in in the CMS

archives promoted collection - not done
article with form- not done
footer menu item- not done

Adding items

Biography
internal link
list entry link
related publications
facebook post
sketchfab
tweet

Sponsor - in related content

name field is mandatory

Al other fields are optional.

There was an error - Value cannot be null. Parameter name: source

Supported by

There was an error - Object reference not set to an instance of an object.