Why does this GridBagLayout have unused empty space and how can I get rid of it?

So I have a JPanel that is split into 2 other separate JPanels (although this is mostly irrelevant). On the left side I have a GridBagLayout that I have organized to have a JLabel at the top, and a JTextArea below it, however the JTextArea isn't directly beneath the JLabel. Instead there is this empty space and I can't figure out why it's there or how to fix it. I'm fairly new to Java in general and GridBagLayout so I could be missing something, but I've tried several things to get it to work. I have the code for this below along with a visual representation of what it's doing. Any help is appreciated.

CODE

    //LEFT SIDE
    GridBagConstraints leftGBC = new GridBagConstraints();
    JPanel leftSide = new JPanel(new GridBagLayout());
    leftSide.setBorder(new EmptyBorder(inset, inset, inset, inset));
    Font titleFont = bb5.comfortaa.deriveFont(Font.PLAIN, 16f);
    leftGBC.gridx = 0;
    leftGBC.gridy = 0;
    leftGBC.weightx = 1;
    leftGBC.weighty = 1;
    leftGBC.anchor = GridBagConstraints.NORTH;

    JLabel leftTitle = new JLabel("Objective");
    leftTitle.setFont(titleFont);
    leftTitle.setBorder(BorderFactory.createMatteBorder(0, 0, 2, 0, Color.BLACK));
    leftGBC.fill = GridBagConstraints.HORIZONTAL;
    leftSide.add(leftTitle, leftGBC);
    leftGBC.gridy = 1;
    leftGBC.anchor = GridBagConstraints.NORTH;
    JTextArea objectiveArea = new JTextArea(objectiveText);
    objectiveArea.setBackground(leftTitle.getBackground());
    objectiveArea.setEditable(false);
    objectiveArea.setFocusable(false);
    objectiveArea.setFont(bb5.samsung1.deriveFont(16f));
    objectiveArea.setLineWrap(true);
    objectiveArea.setWrapStyleWord(true);
    leftSide.add(objectiveArea, leftGBC);

VISUAL