Why do some messages appear in the network tab?
Those messages have been copied there because they matched your stalk list. The reasoning here is that, if you’re away from the computer for a long time, important messages might have scrolled off the view by the time you get back. Copying the message to the network tab makes sure you don’t miss anything important. It’s also a quick way to catch up after being away for a while. The View > Copy Important Messages menu item can be used to disable this feature.