Review Reminder Emails Stopped Sending

We’ve had this plugin installed for 8 months or so. The Review Reminder emails appear to have sent inconsistently since the beginning with some sending and some stuck on pending. We have a 45 schedule time day delay from when the order changes status from processing to completed. Now 0 Review Reminder Emails are being sent and the “Review Reminder” shows on the order past the date it’s supposed to go out. VillaTheme support mentioned it might be a cron job issue, but did not elaborate and advised I post here. Anyone know why the emails are not being sent?