Versions of DA 2.3.3 GA release (2.3.3.435) has a severe defect, which is if the user changes a poll configuration item such as, monitoring profile, poll rate..etc. It may very likely cause large number of polls to stop.
The fix for this issue is in 2.3.3 August kit and later releases. If customers are on the 2.3.3 GA kit they would probably run into the same issue if they change polling configurations after discovery.