I have a Dell Vostro 3560 using a Validity Sensors VFS5011 fingerprint reader and running Ubuntu 18.10. When I first installed Ubuntu the fingerprint reader worked perfectly for logging into my PC, but later on (About a month later) it abruptly stopped working. I can still set up a fingerprint using the Setings app and it works there but on the login screen it won't do anything. It won't give me an error or anything on the login screen; it will just sit there until the screen times out saying "swipe finger" as I'm swiping it. My guess as to the reason for the sudden loss of function is that an update or something messed it up.