I am using gnome-system-monitor installed with Ubuntu 20.04, and the network graph always shows '0 bits/s', whereas the system-monitor extension (the one in my top bar) shows my actual network usage. The network graph sending line also incorrectly flashes (suddenly changes into a few vertical lines).
EDIT 0: It works fine when I run with sudo, but how can I fix that?
Always says '0 bits/s': 
The yellow sending graph suddenly turns into vertical lines every secondish: 
1 Answer
This was fixed for me in Ubuntu 20.10.