Recently, on the WordPress site, I noticed the problem of sending messages via Contact Form 7 from devices with the iOS operating system.
If you used Google reCAPTCHA, when you clicked on the Send button, the page was updated for a very long time and reCAPTCHA reported a wait error, if you disable reCAPTCHA, then the message was sent after 1-2 minutes.
As it turned out, iOS somehow started blocking AJAX, which was used by default when updating the page.
So to solve the problem, I opened the configuration file wp-config.php and just before the line:
Added a line:
define ('WPCF7_LOAD_JS', false);
If you specify this variable at the end of the file, it will not work.
After this, the messages on iOS started to go immediately.