Classic forms allows us to use formatDate function in the Date/time control, but we are unable to change the Date display format along with displaying the alert message saying "the type doesn't match(different)" in New Responsive Forms.
We would request Nintex to add the feature so that we are able to use "formatDate" function in the Date/time control, too.
Thank you for your feedback, it's greatly appreciated. I’ve now opened this idea for voting. Please continue to share your thoughts, as your input is invaluable to our long-term planning.