I downloaded an app on my phone which checked who was logged into my router. There is an additional device always attached which DOES NOT show up on the Swisscom router admin pages. This means i cannot block the MAC address. I do not have NAS or any options like that. I have asked Swisscom what this is but so far they have said nothing. I am fairly sure this is some surveillance on my internet traffic but i want to know if anyone else has this issue. If so how do i stop that unknown invisible device attaching itself to my router.