Shortcode of the contact form is different than you used https://prnt.sc/tfgdq6
I see the error in the red border. It means that something is wrong with your mail server https://contactform7.com/faq/i-get-an-error-message-with-a-red-border-so-how-can-i-solve-this/
I would suggest you contact your host for support. They may be able to check the error logs to find out the reason for the failure. We can do nothing with this because it’s not related to theme files or theme settings.
