Within the Fleet Manager, I can see an overview of all created events, yet I only see them within the northbound API. The southbound API/MCL does not find them. Are there any special conditions or configurations for the events to be routed to the asset?
This is correct behavior. If you want to send event information southbound, there is an API to do so. Events are never sent southbound by default or automatically. To send events forward to the southbound API, you need to use the Event Push Job.
You can find further information on the API and how to set this up in the MindAccess_Developer_API reference documentation that is updated regularly in the Siemens Industry Online Support.