websitebaker mobile button icon not shown

this does not apply to all mobile devices, some display without problems, for example iphone
while android has problems

when I call for the first time a page that has no children and renew the menu, the icon does not appear, but if I go to a page that is a child of another page and return to the initial page, the icon is visible
what’s the problem

Here is my site Read-Only: LINK
(how to share your site Read-Only link)