I just installed Lubuntu 17.04. It did not recognise the WiFi card I had in the MB, so I took a TP-Link WN722N USB stick. The system immediately recognised the USB WiFi stick and offered networks to connect to. But at any attempt to connect, the system just gives up after a while without explanation. I do not have any special settings, just regular AES password protection. What can I do other than search for a different distribution?
I tried opening
sudo leafpad /etc/NetworkManager/NetworkManager.conf
added the line
then I restarted the service
sudo service network-manager restart
...and I got connected! The browser still has a problem connecting to the internet, but I guess that is a different issue. Thanks for the suggestions.