Ubuntu 18.10 - Issue with screen inactivity and lock screen

Clean installation of Ubuntu 18.10 beta

I want the screen to turn off after 1 minute of inactivity, but I do not want the system to be locked when it is activated again. So I do :

gsettings set org.gnome.desktop.session idle-delay 60
gsettings set org.gnome.desktop.screensaver lock-enabled false

The screen turns off after 1 minute of inactivity. The problem is that after that when I try to access the system it is stuck at a purple screen similar to the one of the lock screen but with no input form for password. The only way to access the system, is to suspend the system and then resume.

Do you have any view on this?

Same here after upgrading from 18.04 to 18.10. First tried to disable my extensions. After about an hour working I tried to lock my machine and failed. So not a solution for me.

Googling some more, when I came across Lock screen curtain in Ubuntu 18.10 won't open and a suggestion there was to remove and add gdm3 from terminal:

$ sudo apt remove gdm3
$ sudo apt install gdm3 
$ reboot

Now, half a day working later, 10+ locks, the issue has not returned.

Update 2018-11-16

Issues have returned unfortunately. After going through the bugreport this suggestion came by:

gsettings set org.gnome.shell.extensions.dash-to-dock transparency-mode FIXED

For me this seems to work.

First, install dconf-editor:

sudo apt install dconf-editor

After, start dconf-editor and open path /org/gnome/desktop/lockdown/

Make sure, option disable-lock-screen is disabled.

The same with gsettings:

gsettings set org.gnome.desktop.lockdown disable-lock-screen false