How to reproduce:

• Add annotations in a content type (find an example adding annotations to the article content type in attachments)
• Add content in a Rich text of this content type
• Select some text
  • All annotations are enabled and no one is toggled => OK
• Add an annotation => OK
• Select some text inside the annotation
  • The current annotation is toggled and the other ones are disabled => OK
• Click on the current annotation
  • An annotation inside the current one is added => KO : the current annotation should have been removed