Hello KH,
Maybe it has nothing to do with your problem (I don't use vRops), but in vDP you can configure e-mail notifications (go to vSphere Web Client and enter on the appliance section), so, you would receive in your e-mail a report of the last backup jobs...
Right now I'm looking for the way to monitor that in Zabbix or through SNMP. If I find something (I found how to do it in vDPA, but not in vDP), I will post it.