The problem is when I clear all content with Backspace button causes default

<p><br></p>

tags to be deleted in Summernote 0.8.18

  <script type="text/javascript">
  $(document).ready(function () {
    $('.tinymce-editor').summernote({
      placeholder: 'За допълнителна информация въведете тук.',
      tooltip: false,
      toolbar: [
          ['para', ['ul', 'ol', 'paragraph']],
          ['font', ['superscript', 'subscript']],
      ],
      height:150
    });
  });
  </script>

After that no text can be added unless some of the editor button are clicked. Any solution?