On the front office
When editing/creating content, section override are lost.

The kernel have change between ez 3.8 and 3.9 but why?
In the file kernel\content\action.php

In ez 3.9 you set the section id to 0

                // We should set sectionID to 0 because when publishing eZContentOperationCollection::updateSectionID() will be called
                // and sectionID will be updated
                $sectionID = 0; 

the old one

$sectionID = $parentContentObject->attribute( 'section_id' );

Steps to reproduce

In the override.ini
define one pagelayout per section
In one section create a new content.
->you will lost your pagelayout.