WYSIWYG Full not working on relational edits

From directus created by peremp : directus/directus#1567

Version Info

• Directus version and branch: 6.3.9 and 6.4.0

Imagine that we have a table solutions, a table problems, and a table use_cases as junction table. The table solutions has a M2M field called "related problems".

Steps to Reproduce

1. Create some random problems.
2. Create a solution, and in the "related problems" field choose some of the existing problems created on step 1.
3. Save.
4. Edit the solution and click on any of the related problems added on step 2.
5. Edit something on the problem
6. Click "Save".

Expected Behavior

The problem changes are saved.

Actual Behavior

The changes are not saved.

Also

If the problem table have a "WYSIWYG" editor, it is not loaded when accessing to the problem through the solution edition.