Approved Email Notifications not sent

Pending email are attached with a link to approve bookings – this link does approve the booking but it doesn’t set the email to send so no approved emails are sending.
Emails notifications are switched on

This is an apache warning at the same time if that is of any help.
mod_fcgid: stderr: The is_ajax function is deprecated since version 6.1.0. Replace with wp_doing_ajax.