Notify Post Authors That Their Post Is Going To Expire stopped working

The function "Notify Post Authors That Their Post Is Going To Expire" was working well but recently (in the past 6 months) stopped working. The post is expired correctly but the author is not sent an email.  We have plugin "Email Log" so as an admin I can see there was no attempt to send an email to the author. We are using version Version 1.2.8 of Kronos Post Expirator. I attached a screenshot of the settings related to this problem. I hope you can help resolve this issue.