I just noticed that the form submission buttons in my app were deprecated, so I replaced them. But when I tried to add the options for disabling an invalid form and resetting the form on success to forms inside modals, I couldn't find the options. This is a bug that is being fixed on high priority by the Appsmith team.
The issue reported is that form submission buttons were deprecated in a recent version update and were replaced, but the options for disabling invalid forms and resetting forms on success were not visible for forms located within modals. The expected behavior was for these options to be available on all forms, whether inside modals or not.
The Appsmith team confirmed that this was a bug and is fixing it on high priority. In the meantime, though the options are not visible, they are set to true when a form is added to a modal. So, these options will still work, but users may not be able to see them in the settings.
Code examples were not necessary for this solution.