Why is there no confirmation of sending an email in contact form 7?

Question

CAPTCHA

Good afternoon. There is a contact form with a recaptcha on board. If the form is filled out correctly, the letter leaves and reaches the recipient, but there is no confirmation of sending. At the same time, after some time (20 seconds), the captcha reports an error: "Check time has expired. Check the box and try again." Please, help.