There are occasionally reported issues of the WP Fusion settings page not saving fully, especially the options under the Addons, Integrations, and Advanced tab.
This is related to PHP’s
max_input_vars setting, which controls how many options on a single page can be saved at one time. If you have a lot of integrations running, or a lot of custom fields configured, the number of options on the Contact Fields tab can exceed this number.
max_input_vars for many hosts is 1,000 inputs. The recommended setting for WordPress sites is 5,000 inputs. You can contact your host and ask for this number to be increased, and then the settings will save fully.