We experienced issues with shared layout on few of our pages. Presentation assembling seemed not following Presentation Detail Information Flow.
Based on Sitecore documentation this is a flow
- SharedLayout option uses __Rendering field
- FinalLayout option uses __Final Rendering field
- Going from right to left, if a field has a layout delta, it goes to the field to its left to gather more presentation information.
After the investigation we noticed that on Save Button click in Experience Editor, the full share layout is saved and not the delta in __rendering fields. ( in case when a page is inheriting renderings from standards values).
Sitecore provided us with a patch. You can request one – the reference number is 144214