The Anyconnect has a customer experience feedback module (CEF), which transmits non-personal data to Cisco. This is described in detail described on the manufacturer's page.
The CEF module is activated by default after installation of the Anyconnect. However, it is deactivated during the first connection to "vpn.rwth-aachen.de". Theref no further data will be collected captured by the CEF module and sent to Cisco.
If you wish to deactivate this function under Windows without connecting to "vpn.rwth-aachen.de", please follow this guide by Cisco.