By setting the parent element:
alwaysShow:true
Parents with multiple child routes (menus) under the parent route (menu) can be displayed normally, only the parent route (menu) with one child route (menu) under the parent will not be displayed. Because there is only one child route (menu), it is caused by the parent's hidden and non-displayed attribute. Set alwaysShow: true at the parent level to ensure that the parent level with only one submenu is displayed.