Text field and checkbox inside widget

Hi all! I just started using trying CKEditor. I'm following the widget tutorial and created a widget with a checkbox and text field (input type="text") inside. However I'm facing the following issues:

• On Chrome the checkbox cannot be checked
• On Firefox, IE and Chrome I cannot type in the text field. On Firefox and Chrome I can't even focus it, on IE the focus disappears immediately after it has been focused

Is there a way to implement a widget with such fields where the user can input data?

Here is my code:

CKEDITOR.plugins.add('simplebox', {
    requires: 'widget',

    icons: 'simplebox',

    init: function( editor ) {
        editor.widgets.add( 'simplebox', {
            button: 'Create a simple box',
            
            template:
                '<div class="simplebox">' +
                    '<h2 class="simplebox-title">Title</h2>' +
                    '<div class="simplebox-content"><p>Content...</p><input type="checkbox" />fasfasf<input type="text" /></div>' +
                '</div>'
        } );
    }
});