No, Ja Stark is fine, tapping on the menu item (Pages, for example) opens the dropdown submenu and clicking again on the main menu item "Pages" closes the submenu. It doesn't work like that and the submenu doesn't close with T4 Blank, but also with Ja Educatsy and other templates. You can also try it with Firefox View Mode or Android phones.
Looking through the various files to understand why such a different behavior, I found that a part of that base.js file is different.