Steps to reproduce the problem
1. Connect to a database in Data Studio
2. Click on Tables in the Administration Explorer
3. The right pane will shows a list of tables, click on a table (make sure the table has RI relationships with multiple tables)
4. On the properties view, click the Relationships tab
The Relationships tab should display ALL the tables that has RI with the currently selected table. In fact, it only display some of the tables. This problem exists for both Data Studio 3.1 and 3.2.
In addition, I found a work around, you have to click on the Constraints on Administration Explorer, and then scroll to the bottom on the constraint list of the right pane. Then, when you go back to the previously selected table, it will display all the RI under Relationships tab.