Sophos Security Heartbeat server certificate refreshed

Since upgrading to V19 I’m receiving following Notification email every day:

“Sophos Security Heartbeat server certificate refreshed

You are receiving this auto-generated message from Sophos Notification system to inform you about your Sophos Security Heartbeat server certificate was about to expire but had been successfully refreshed.”


(seen on two virtual software firewalls since eap 1)
Is this heartbeat-certificate really valid one day, so it need to be renewed every day or is this an issue?