Hello @LiveHus,
I would suggest to check the "Execution Mode" of the service once and confirm if it's set to "Asynchronous (Recommended for long-running services)" with "View results with a map service" enabled, screenshot below may helps:
If yes, just try by unchecking the "View results with a map service" and run the tool to see it the second Feature Layer is created?
Additionally, If the above doesn't help can share the "Info" level logs for the Geoprocessing service. To set the logging level for the Geoprocessing Service specifically, follow the below document:
Enabling info-level geoprocessing messages : Troubleshooting geoprocessing REST services—ArcGIS Server | Documentation for ArcGIS Enterprise
Once, you enable this run the tool again and navigate to "ArcGIS Server Manager" > Site > Jobs > Under Service select the GP service and query. This will show you the Job ID generated for the latest run of the tool. Once you open that, it will show you details of the JOB run.
Hope it helps!
-Archit