So, my network monitor told me that there's IPv6 traffic. Weird, I don't
have IPv6 at home. Turns out, it's just on the loopback interface and
only some TCP SYNs and their corresponding RSTs, since there was no
daemon listening.

Once I closed Chromium, it was gone.

What?

Ah. This starts as soon as I open the inspector window using F12.

What?