If a menu does not have an id, its label will appear as one of the submenus

Having this json menu structure:

[
        { "label": "I dont have an id",
         "submenu": [
                {"label": "30", "submenu": [{"label": "submenu_from_no_id"}]},
                {"id": 31,
                 "label": "value31"},
                {"id": 32,
                 "label": "value32"},
                {"id": 33,
                 "label": "value33"},
                {"id": 34,
                 "label": "value34"},
                {"id": 35,
                 "label": "value35"},
                {"id": 36,
                 "label": "value36"},
                {"id": 37,
                 "label": "value37"},
                {"id": 38,
                 "label": "value38"},
                {"id": 39,
                 "label": "value39"}
         ]
        }]

The last of the submenus, the one with the id 39, instead of having the label "value39" it will show with the label "I dont have an id". See attached screenshot.