Clients not updating when Network Application Monitoring is Enabled

Hi, I was trying to enable network application monitoring so I can "Allow and Log" when an application change is deteced on client computers. But when I enable network application monitoring, I notice the policy doesn't update on all of the clients computers (stays at the old policy serial number). When I disable network application monitoring, the policy starts updating again. I am running SEPM 12.1.7061.6600 on Windows Server 2016. Any help on this would be appreciated.

Thanks