How to reproduce

• define a content that contains a date

  <cms:metadata name="start-date" type="date">
  						<label i18n="true">CONTENT_ALERTE_STARTDATE</label>
  						<description i18n="true">CONTENT_ALERTE_STARTDATE_DESC</description>
  					</cms:metadata>	
  					<cms:metadata name="end-date" type="date">
  						<label i18n="true">CONTENT_ALERTE_ENDDATE</label>
  						<description i18n="true">CONTENT_ALERTE_ENDDATE_DESC</description>
  					</cms:metadata>	
  

• In the back-office create a page with this content using the date
• copy and paste the page with duplication of the content

Actual behavior

• the content is not editable