ICEpdf viewer not rendering fonts properly

Question

I have a class to test an ICEpdf viewer in a JFrame with ICEpdf 6.2.2, the newest in the maven repository. When I open the PDF I'm trying to render in Ubuntu's default PDF viewer it displays correctly, however, when displayed in the ICEpdf viewer the font spacing is wrong and the actual font is replaced with a sans serif font. Here are screenshots of the GCC manual in my ICEpdf viewer and the default Ubuntu PDF viewer. I have used pdffonts to gather what the fonts used in the manual are. In my code I have set org.icepdf.core.awtFontLoading to true, which didn't fix the issue. My code is the following:

import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Toolkit;
import java.io.File;
import java.util.Properties;
import java.util.ResourceBundle;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;


import org.icepdf.ri.common.SwingController;
import org.icepdf.ri.common.SwingViewBuilder;
import org.icepdf.ri.util.PropertiesManager;

public class TestPDF {

    JFrame mainFrame;
    final Dimension SCREEN_SIZE = Toolkit.getDefaultToolkit().getScreenSize();

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    TestPDF window = new TestPDF();
                    window.mainFrame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    public TestPDF() {
        mainFrame = new JFrame();
        mainFrame.setTitle("Test");
        mainFrame.setSize(new Dimension((int) (SCREEN_SIZE.getWidth() / 2), (int) (SCREEN_SIZE.getHeight() / 2)));
        try {
             UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
        } catch (ClassNotFoundException | InstantiationException | IllegalAccessException e) {
            e.printStackTrace();
        }
        PropertiesManager properties = new PropertiesManager(System.getProperties(), new Properties() {
            {
                setProperty("application.showLocalStorageDialogs", "false");
                setProperty("org.icepdf.core.awtFontLoading", "true");
            }
        }, ResourceBundle.getBundle(PropertiesManager.DEFAULT_MESSAGE_BUNDLE)) {
            {
                setBoolean(PropertiesManager.PROPERTY_SHOW_TOOLBAR_ANNOTATION, Boolean.FALSE);
                setBoolean(PropertiesManager.PROPERTY_SHOW_TOOLBAR_FORMS, Boolean.FALSE);
                setBoolean(PropertiesManager.PROPERTY_SHOW_TOOLBAR_UTILITY, Boolean.FALSE);
                setBoolean(PropertiesManager.PROPERTY_SHOW_TOOLBAR_ROTATE, Boolean.FALSE);
            }
        };
        SwingController controller = new SwingController();
        SwingViewBuilder factory = new SwingViewBuilder(controller, properties);
        JPanel viewerComponentPanel = factory.buildViewerPanel();
        controller.getDocumentViewController().setAnnotationCallback(
                new org.icepdf.ri.common.MyAnnotationCallback(controller.getDocumentViewController()));

        try {
            File pdf = new File(this.getClass().getResource("/pdfTest/gcc.pdf").toURI());
            controller.openDocument(pdf.toString());
        } catch (Exception e) {
            e.printStackTrace();
        }
        mainFrame.add(viewerComponentPanel);
    }
}

pdffonts output:

name                                 type              encoding         emb sub uni object ID
------------------------------------ ----------------- ---------------- --- --- --- ---------
PNWIQB+CMBX12                        Type 1            Builtin          yes yes yes      7  0
URLEKE+CMR10                         Type 1            Builtin          yes yes yes      8  0
ZXGTJI+CMCSC10                       Type 1            Builtin          yes yes yes      9  0
YPVIBW+CMTT10                        Type 1            Builtin          yes yes yes     18  0
LNUCPW+CMSY10                        Type 1            Builtin          yes yes no      19  0
XLCDGX+CMR12                         Type 1            Builtin          yes yes yes     49  0
GPANTX+CMMI12                        Type 1            Builtin          yes yes no      50  0
TOPQZD+CMTT12                        Type 1            Builtin          yes yes yes     51  0
DOAFRX+CMMI10                        Type 1            Builtin          yes yes no     124  0
HMFXDM+CMTI10                        Type 1            Builtin          yes yes yes    804  0
FEUAVN+CMSL10                        Type 1            Builtin          yes yes yes   2558  0
DISGYX+CMSLTT10                      Type 1            Builtin          yes yes yes   2626  0
RQLRQN+CMTT9                         Type 1            Builtin          yes yes yes   2634  0
FRMZZY+CMR9                          Type 1            Builtin          yes yes yes   2635  0
KGBAZG+CMB10                         Type 1            Builtin          yes yes yes   2832  0
BNSWRJ+SFRM1095                      Type 1            Custom           yes yes no    3233  0
HSQXWC+CMR7                          Type 1            Builtin          yes yes no    3527  0
GINCXO+CMMI7                         Type 1            Builtin          yes yes no    4887  0
FFYKXD+CMSS10                        Type 1            Builtin          yes yes yes   4963  0
PXBGHL+CMSY7                         Type 1            Builtin          yes yes no    4989  0
QUTMWC+CMSY9                         Type 1            Builtin          yes yes no    5049  0
GXLYQS+CMSL9                         Type 1            Builtin          yes yes yes   6771  0
BCUDVF+CMBXTI10                      Type 1            Builtin          yes yes yes   7002  0
PQILTH+CMMI9                         Type 1            Builtin          yes yes no    7364  0
WOJFXW+CMR8                          Type 1            Builtin          yes yes yes  12564  0