The legend of the caption box is partially redundant in combination with the legend on the right.
In addition, it collides with the numeric entries.
Is there a setting to hide the legend of the caption?

dt = Open( "$SAMPLE_DATA/Big Class Families.jmp" );
gb = Graph Builder(
Graph Spacing( 4 ),
Variables( X( :age ), Y( :height ), Overlay( :sex ) ),
Elements(
Box Plot( X, Y, Legend( 4 ) ),
Caption Box( X, Y, Legend( 5 ), Summary Statistic( "Mean" ), Location( "Graph per factor" ) )
)
);