Still can't update or install devtools via WLAN.
When trying to install devtools in terminal (apt-get) I get timeouts.

New problem: can't open devtools-networking.
It shows up as being installed, but when I try to open it, it says:
"The following packages also will be installed when installing devtools-networking: tcpdump"
When hitting OK, it just fails to open or install anything. And that is with wifi AND cellular connection!
When trying "apt-get install tcpdump" and "apt-get install devtools-networking" it says already installed.
What's wrong here?