Booking calendar is not working on mobile devices or small screen size intext:

Please check it on small screen or mobile devices.

Hello.

This issue exist, because you have inserted the booking form into the section at the page, which is hiding when someone open this page at mobile devices.
Its not only about the Booking Calendar but any other picture or text at this page.

Your actual theme have these CSS classes: hidden-xs col-md-7 for that section of the page, which is hide it.

You need to reinsert the booking form into the section which is visible at the page for any type of screen resolutions. For example at the right sidebar.

Otherwise, please contact support of your theme about resolving of issue of hiding that section of page in mobile devices.

Kind Regards.