Leaf's with no children do not display checkboxes or group icons.

[ApiumJacob]

/*! jsTree - v3.3.12 - 2021-09-03 - (MIT) */

On the front page of jtree.com there is an example with checkboxes and groupt icons:

However, when I make my tree the leaf don't show the group icons nor checkboxes:

    $('#jstree_div').jstree({
        "core" : {
            "multiple" : true,
            "themes" : {
                "variant" : "medium",
            },
            data : [{"id": "1", "text": "Hello", 
                     "icon": "/static/images/info.svg", 
                     "a_attr": {"title": "stick to your day job"}, "children": ["Thing 1", "Thing 2"] },
                    {"id": "2", "text": "World", 
                     "a_attr": {"title": "never take advise from a stranger"}, 
                     "children": ["Thing 1", "Thing 2"] }
                   ]
        },
        "checkbox" : {
            "visible" : true,
            "keep_selected_style" : true
        },
        "plugins" : [ "sort", "checkbox", "wholerow" ] //, "contextmenu" ] //]
    });

Anyone have a hint on what's going on here?

[ApiumJacob]

Same thing happens if I define my tree in HTML:

                    <div id="jstree_div">
                        <ul>
                            <li>Hello
                                <ul>
                                    <li>Hello</li>
                                    <li>World</li>
                                </ul>
                            </li>
                            <li>World</li>
                        </ul>
                    </div>

Javascritpt:

    $('#jstree_div').jstree();

[ApiumJacob]

Today I have been able to get the check boxes and icons to appear if I set "children" of a given node to true. Although there are no children this cause the checkbox and icon to appear but also add the expansion triangle next to node:

    $('#jstree_div').jstree({
        "core" : {
            "multiple" : true,
            "themes" : {
                "variant" : "medium",
                "expand_selected_onload" : true,
            },
            data : [{"id": "1", "text": "Hello",
                     "icon": "/static/images/info.svg",
                     "a_attr": {"title": "stick to your day job"},
                     "children": [{"text": "Thing 1", "children": true}, {"text": "Thing 2", "children": true}]
                    },
                    {"id": "2", "text": "World",
                     "icon": "//jstree.com/tree.png",
                     "a_attr": {"title": "never take advise from a stranger"},
                     "children": [{"text": "Thing 1", "children": true}, {"text": "Thing 2", "children": true}]
                    }
                   ]
        },
        "checkbox" : {
            "visible" : true,
            "three_state" : true,
            "keep_selected_style" : true
        },
        "plugins" : [ "sort", "checkbox", "wholerow" ] //, "contextmenu" ] //]
    });

[ApiumJacob]

Interestingly if I change the theme to default-dark then everything breaks:

		<link rel=stylesheet type=text/css href="{{ url_for('static', filename='jstree/themes/default-dark/style.min.css')|autoversion }}">

Both style.min.css and style.css produce this output:

		<link rel=stylesheet type=text/css href="{{ url_for('static', filename='jstree/themes/default/style.min.css')|autoversion }}">

		<link rel=stylesheet type=text/css href="{{ url_for('static', filename='jstree/themes/default/style.css')|autoversion }}">