CKEDITOR.replace() on appended textarea

On page load i can have between 0 and 10 textareas, on click I am appending new textarea:

container.innerHTML += content;

And now I need CKEDITOR on that textarea. If I trigger:

CKEDITOR.replace( selector );

Everything in existing textareas/ckeditors is lost.

My Code:

function addField( event ) {
  event.preventDefault();

  let container = document.getElementById('about_content');
  let childNumber = container.childElementCount;
  let content = about_html.replaceAll( '%nr%', childNumber )
  container.innerHTML += content;

  ckEditorTrigger( 'tiny_editor_' + childNumber );
}

function ckEditorTrigger( selector ) {
  CKEDITOR.replace( selector );
}