The following error appears in a mobile device's management history in inventory:
"The JSS has received a feedback error from the APNs server"
Casper Suite v8.5 or later
Starting with v8.5 of the Casper Suite, the JAMF Software Server (JSS) receives feedback from the APNs server when there is a problem sending a push notification to a device. This error may appear if the Apple Push Notification service (APNs) server communicates with the device and receives an error back.
Verify that the MDM profile is still installed on the mobile device.