I have recently upgraded a few of our Ubuntu machines to Ubuntu 18.04. I have managed to configure everything and everything seems to be working fine, apart from the lock screen. 

It seems that if the computer is left idle for longer periods of time the lock screen will not accept the credentials any more and restart of gdm or the computer has to be done for it to work again. 

I found [this bug report](https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/1792843) which seems to describe the problem.

Can anyone advise me if there has been any work on this or if anyone has found a workaround?