Related Record Opens as a New Tab Instead of Subtab in Console Apps

To resolve the issue where a related record opens as a full tab instead of a subtab in Salesforce Lightning Console Apps, ensure the parent relationship field is included on the child record's page layout.

In addition, user's profile tab settings for the objects involved need to be set to "Default On" see Show or Hide Tabs for Users in Salesforce for more details.

The Workspace API relies on application cache to determine parent-child relationships. If the relationship field is absent from the cached record data, Salesforce defaults to opening the record in a new full tab. Adding the subtab's object's parent relationship field to the page layout and setting user's tab visibility for the objects ensures it is included in the cached data, enabling correct subtab navigation.

Having the parent ID for the record and enabling tab visibility for objects are a requirement for the console's navigation rules to work as expected.