I have seen this issue several times but I cannot pinpoint it to some specific scenario.   I have seen it against APEX and Drools.    The problem manifests occasionally when trying to deploy policies when an error message is returned as one of the PDPs is not in the group.

The PAP recovers though and a subsequent deploy operation goes through OK without any manual intervention.

One note is that PAP now sends frequent STATE changes to ACTIVE, I don't think this is the same as in previous releases.