Form loading and then disappearing on front-end

The form loads successfully and displays very briefly, and then disappears from the DOM. It appears that it’s happening on load of VFB JS.

Viewable here: http://test.smedleycanoe.ca/become-a-sponsor/

EDIT: After some testing, it appears that sections are the culprit. Any fields that are in a section disappear with the section.

https://wordpress.org/plugins/visual-form-builder/