The default behavior of the Divi Theme's accordion module is to start with one toggle open and the rest closed. Then clicking on a closed toggle opens it and closes the originally open one. One thing you might notice is that, despite clicking on the open toggle having no effect, the mouse cursor changes to the "hand" pointer icon. This might be confusing to users who take this icon as a sign that something will happen when the element under the mouse is clicked. Here's how to prevent the "hand" pointer from showing on open toggles.
Disabling Clicking on Open Accordion Titles
You can suppress the change in mouse cursor by using the following CSS to disable clicking on open accordion titles: