Answer:
The [Synchronization of Selection] and [Show Selected Objects] buttons have probably been deactivated in the table window. Switch them on again (see Image 01). Then, an object whose table row is selected is also highlighted in color in the graphic. Conversely, if an object is selected in the graphic, the relevant line is also shown in the table and highlighted in color.
The objects that are clicked in the Data navigator are also selected in the graphic (see Image 02).
