I think i fixed the original request, which was to make 1001 unreachable. How it works i don't understand.
I removed the call forwards on 1001 so that there are no call forwards left/active.
Then i applied Call Rerouting First and Second Alternative where everything is set to Normal without a destination.
Apparently, i get a out of service tone for this specific extension right now. Problem solved, but how?
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