IIRC I’ve seen this and reported it on the forum, but don’t remember what was the cause or if it relates to your case in any way.
EDIT: Ns8-sogo: "administrator list" field filtering/validation
On the other case was because of a malformed config file causing some app or app services to auto-restart to infinitum (but not exactly the same).
Check if something pops-out on cluster log.
Monitor top or similar utilities for activity.
use lsof to see what files are being used… as a way to pinpoint where to look at.
just some ideas