When Elementor released their 3.10 version (Main plugin and the Pro plugin) it had some changes that meant that our Elementor plugins would not function correctly for creating or changing pages. The good news is that any page already created in older versions will work fine, it just means you cannot change them yet.
V1.1.2 will be released on the 2nd March, it will also be backwards compatible, allowing existing pages to continue to work for sign-ups. (Any changes will require the mappings to be changed).
Long story short, we originally did the mapping of the form fields in either the SendFox section. This has now had to move to the Advanced section of Form Fields. See the image below.