In order to stop a running auto-discovery, right-click the group or device, and select Pause | For 5 minutes... from the context menu. Monitoring will be paused for 5 minutes, and auto-discovery tasks will be shut down.
Disclaimer: The information in the Paessler Knowledge Base comes without warranty of any kind. Use at your own risk. Before applying any instructions please exercise proper system administrator housekeeping. You must make sure that a proper backup of all your data is available.