appointments+ calendar / reservation page not showing correctly on mobile

I have troubles rendering the calendar/reservation page correctly on mobile devices:the problem being, oddly enough, that the page doesn't show at all the appointments+ section but it displays the share buttons twice.
I tried disabling the share buttons plugin, but the problem is not solved:
instead of the appointments+ section, the share buttons are shown only once(in kind of default mode graphics and even if the plugin is not active).

On desktop screen everything works fine. I even tried to replicate the problem with a user agent switcher for chrome, but the page is rendered correctly

screenshot is from a htc one (M7) using stock browser. The same thing happens on iphone 5 and ipad.

Plugin versions:
Simple Share Buttons Adder v4.3
Appointments+ v1.4.3.1