Case Assignment Checkbox must be displayed on Case Edit Page Layout for Community Users in order for Assignment rules to trigger
|Knowledge Article Number||000193707|
With the introduction of Communities, we made the decision to have the "Assign using Active Assignment Rules" box display on Page Layouts for users to keep the behavior consistent with the rest of the application.
Customers now have the option to uncheck the box to allow greater flexibility within Communities as opposed to Portals.
|Resolution||While we understand that this is not how this used to function in Portals and that you could hide the box with it checked, you may still work around this new behavior by overriding the Page Layout with VisualForce, or designing custom Assignment Rules using Apex logic.
Note: The Napili Template and the Koa template currently does not support the "Assign using Active Assignment Rules" box as a workaround consider using Workflow Rules.