In Workspace One, check the expiry date of the APN in Groups and Settings > All Settings > Devices and Users > Apple > APNs for MDM. Check Test Connection.
Click Renew and download the AirWatch Certificate Request ( MDM_APNsRequest.plist ).
Go to Apple and login with relevant account and navigate to the Apple Push Certificates Portal.
Click renew on the expired certificate and upload the AirWatch Certificate Request from earlier and click Upload.
Download the newly generated certificate.
Back in Workspace One upload the new Apple issued Workspace ONE UEM MDM certificate (.pem)* and enter the account name.
Next verify the new certificate and enter your security pin.