Change record status: 
Project: 
Introduced in branch: 
8.x-5.x
Introduced in version: 
8.x-5.0-rc13
Description: 

When a container element (ie fieldset, details, etc) was being rendered as text all child elements were being appended to the render array.

This caused conflicts with the container's title and any child element's named 'title'.

Impacts: 
Themers