O365 licenses limit changes are not propagated to MOP. The following error can be found in
Sep 15 15:38:25 osscore.mnnode.com : ERR [SYSTEM 1:35349:f10e7b70 SAAS ]: [ APSC] Error while waiting for notifications: FATAL: terminating connection due to administrator command CONTEXT: SQL statement "SELECT pg_sleep(0.100)" PL/pgSQL function "aps_wait_for_event_notifications" line 33 at PERFORM
http://parallels.com/aps/events/pa/subscription/limits/changed events can not reach the endpoint, it is caused by the software-related issue #APS-29199: Events may stop processing due to exception in event listener.
Please contact your TAM/PTA to trace the status of the issue. As a workaround, please restart pem service on OA management node.