I have added the custom font using the method below but that font is only working in few cases

There is one font issue when i click on any element it not show the current font of the element, i added custom code for add my custom fonts. code work perfectly but it not show the selected font by default when i select an paragraph or any text.

editor.on('load', function () {
    styleManager = editor.StyleManager;
    fontProperty = styleManager.getProperty('Typography', 'font-family');
    var list = [];
    fontProperty.set('list', list);
    list = [
        fontProperty.addOption({value: "'Oswald', sans-serif", name: 'Oswald'}),
        fontProperty.addOption({value: "Helvetica Neue,Helvetica,Arial,sans-serif", name: 'Helvetica'}),
        fontProperty.addOption({value: "sans-serif", name: 'sans-serif'}),
        fontProperty.addOption({value: "Times New Roman", name: 'Times New Roman'}),
        fontProperty.addOption({value: "Arial Black", name: 'Arial Black'}),
        fontProperty.addOption({value: "Tahoma", name: 'Tahoma'}),
        fontProperty.addOption({value: "Verdana, Geneva, sans-serif", name: 'Verdana'}),
        fontProperty.addOption({value: "Courier New Courier, monospace", name: 'Courier New Courier'}),
        fontProperty.addOption({value: "'Lato', sans-serif", name: 'Lato'}),
        fontProperty.addOption({value: "'Open Sans', sans-serif", name: 'Open Sans'}),
        fontProperty.addOption({value: "'Montserrat', sans-serif", name: 'Montserrat'}),
    ];
    fontProperty.set('list', list);
    styleManager.render();
});

Originally posted by @hgphpdev in https://github.com/artf/grapesjs/issues/857#issuecomment-443104577