How to render a paragraph 'Text (formatted, long)' as full HTML, not escaped
If you want to render a formatted text field you have to use the render element processed_text:

  {% set paragraph =  item['#paragraph'] %}

  {% set body = {
    '#type':   'processed_text',
    '#text':    paragraph.field_rn_acc_1.value,
    '#format':  paragraph.field_rn_acc_1.format,
  } %}

  &lt;div id="{{ paragraph.field_rn_acc_abbr.value }}-1" class="panel-collapse collapse"&gt;
  {{ body }}
  &lt;/div&gt;