Unable to add an optional compound (and safe the document) in a contentblock in a document when there is also an html field

Issue:

An editor is not able to add an optional compund within a contentblock when the contentblock also contains an html field and was already saved. The editor is after the occurence of the issue also not possible to save the document. 

This has to do with the fact that the compound was added under water (the ajax call was done), but there was not refresh of the model. 

No errors in either the console (of the browser) or in the logs from hippo were found/shown

The issue was found to occur on BRXM 14 and 13. This issue blocks the use of contentblocks with compound fields.

Reproduction issue in CMS:

Below is the setup of the archetype to reproduce the steps (or use the accompanied zip project)

• Login to the cms as an editor
• Go to a sample content document
• Edit the document
• Add a contentblock called: ctablock
• Add text into the HTML field of the contentblock
• SAFE the document (do not click DONE)
• Try to add the optional linkblock within the ctablock
• Result: no link block seems to be added, the browser console shows an ajax call, trying to safe the document does not work as the invisible linkblock has required fields - no errors can be found in either the browser console or hippo logs

Setup of archetype to reproduce above steps:

Below are the steps to recreate the correct setup for the issue in the archetype.

• Checkout a new archetype version of BRXM 14
• Start the project
• Use essentials to add simple document with test content and contentblocks feature
• In the CMS with the documentfield editor add the following two compounds:
  • Linkblock with the fields 
    • label - string - required field
    • url - string - required field
  • Ctablock with the fields
    • html - html field
    • linkblock - just created linkblock type - optional field
• In essentials use the contentblocks configurer to add contentblocks to the simple document type
  • add the ctablock contentblock

Note: Attached in the zip is a project with the above setup from the current archetype which includes simple document and contentblocks from essentials and has added a specific contentblock with an html field and a compound for a link with 2 required fields.