Hello Christian,
Private network is selected under Manage networks.
I can browse the NAS using Windows explorer and have no issues transferring files. The Asustor Control Centre is used to update the Asustor applications and gives access to configuration settings. I also cannot use the WOL feature. If I disable the firewall the Asustor software and WOL is accessible, and I can put the unit to sleep. I have added two .exe files from the Asustor application under Program Files to the Application Rules and have allowed full access under the firewall options, both incoming and outgoing.