How to add multiple TinyMCE Editor with reactive form validation on 1 page (Angular)

Need help on adding custom validation on the TinyMCE Editor.

I want to add custom maxLength validation on the tinyMCE Editor (maximum 10 charactors).
Its working when i do it with 1 editor but doesnt work when i add multiple editors.

Note: Please reload the codesandbox link if get any error.

codesandbox link: https://codesandbox.io/s/tinymce-multiple-editor-validations-t8ud5?file=/src/form/form.component.html