It took me some time to understand that application logging requires the non-portable version which I used some time and worked quite well. I only want to track my WWAN so I enabled "All Mobile Broadband Connections".
Now I installed the non-portable version and activated "Ignore local traffic within the LAN". Unfortunately the interface selection turns grey now suggesting that all traffic is logged (including WiFi)
In "Networks" I can select only the MAC address which is used when connecting via WWAN. However, is this really reliable? Is the Gateway MAC address really always and guaranteed the same? (at least for Ethernet, it definitely changes!!)
Apart from this, there is another subtle problem: Whereas with the configuration above the general traffic seems to be logged for WWAN only, the data in "Applications" comes from all connections. For example, right now I am connected via Wifi (the networx icon is grey) but the traffic in the "Applications" tab still counts traffic from the Wifi interface
Thank you!