So, I deactivated the planned task in the task scheduler and re-activated Duplicati in the autostart-tab in the task manager.
I rebooted … and nothing happend.
When I opened a browser that still had the web-UI tab open it wasn’t able to load it. So it looks like it completely fails to start.
This is the case on both of my machines. (Laptop and Desktop)
This seems to be the same / a similar problem? https://forum.duplicati.com/t/autostart-as-admin/10626?u=a5tro