This works on Debian Buster. Previously updated
firmware-realtek to the
backports version. I don’t think it maters, as the symptoms were as below before and after.
If you are on Ubuntu 17.04 or Debian 9 and possibly other distributions and you see a list of access points, but can’t connect try this (it works around a bug that prevents users from connecting to a network with a USB wifi adapter):
Add to the bottom of the file:
Save and run:
systemctl restart NetworkManager