Calendar monthly view only shows one month

Most people are not going to be able to see the page of concern because it is a members-only area and should be locked out of it; however, as we are developing our calendar, when I try to use the "monthly" default view, it won't let us use the arrows at the top to switch between months. When I switch to "list" view, all of the events are available. 

The link to the page is https://www.ransburgbsa.org/staff-events