got the same problem..
I can click 10 times in a row on “Send”, but nothing happens.
I get the 10 mails, but no fail/success messages..
No plugins are active (except CF7)
Using: https://themeforest.net/item/john-smith-ajax-portfolio-wp-theme/4199227
The Contactform: https://yukan-graphy.com/#!/?page_id=2530
