Why is my Cache Health Monitor Flakey?

 We have recently upgraded to Agile 9.3.0.1. Since we did we noticed that sometimes Administrator changes were not always being updated in the Application. We are running a F5 load balancer so we focused our attention on that and the possibility that there was a cache somewhere that must not be refreshing. Some users would see the changes others would not. No rhime or reason.  In the process we stumbled on the Health monitor cache so we started using it to 'synchronize' our changes and it seemed to work just great.

Since then we noticed that on one occasion we were not able to sync or clear the cache for a couple of changes for at least 24 -36 hours. Then all of a sudden a half dozen changes we made a week ago (and had cleared before) showed up again. At that time we were able to clear all of the items in the cache.