By examining the _internal logs I found the following, Metric Error:
ERROR Metrics - Metric with name thruput:thruput already registered
It is reported by Universal Forwarders of several Clients spread over the entire day (with peaks in the morning hours - so I suppose that it's related to the client's start-up)
The interesting thing is, that all of these clients are still reporting events to the Indexers...
Why does this happen?
And how can I avoid this?