The subject of the letter in the email received from the site

Good afternoon, a question about the feedback forms. In MODX Revolution 2.7.2-pl, when you receive an email info message, the subject line is “” Message from the site “site name” & validate = feedba ", how to remove whatever is written in the subject line & validate =` feedba ".

                    [[!AjaxForm?
                        &snippet=`FormIt`
                        &form=`AjaxForm.feedback`
                        &hooks=`email`
                        &emailTo=`[[++emailsender]]`
                        &emailFrom=`[[++emailsender]]`
                        &emailTpl=`formFeedback`
                        &emailFromName=`[[++site_name]]`
                        &emailSubject=`Сообщение с сайта «[[++site_name]]»` 
                        &validate=`feedback_fio:stripTags, feedback_email:email:required, feedback_message:stripTags:required:maxLength=^500^, feedback_antispam:maxLength=^0^`
                        &submitVar=`feedback_btn`
                        &validationErrorMessage=`В форме содержатся ошибки!`
                        &successMessage=`Мы ответим вам в ближайшее время.`
                        &frontend_css=``
                        &hooks=`spam,chekSpamProtectionMessageKey,email`
                    ]]

Do you still receive the & feedba if you try removing <<++site_name>>?

&emailSubject=Сообщение с сайта

All I can think of immediately is perhaps there is an <a mailto:"& validate feedba"> hiding somewhere in the code. This may not fix your problem, but maybe it can help