No more 'switch user' from sddm

Solution 1:

In my experience, the simplest workaround for this (until 21.04 comes out) is Ctrl-Alt-F2 (F3, F4,...), log in in console mode and type startx.

Solution 2:

I could not find a definitive fix for what, in my opinion, appears to be a major theme flaw for the default Kubuntu KDE plasma desktop.

This was my approach to a workaround:

Add 'User Switcher' widget to the desktop:

Right click on an empty spot in the desktop and from the menu select 'Add Widget'. Type 'user' in the search bar. Add it to the desktop.

Change the default login screen:

Application Launcher->System Setting->Startup and Shutdown+Login Screen(SDDM)

I choose 'Get New Login Screens' and chose one the had a drop menu for the users. In my case it was a screen called 'Sugar Candy'.

Problems I encountered with this workaround:

Locking the session only allowed the locked user to login. To switch user required current user to log back in then use switch user widget.

If the current user started a new session, it would start up an unusable session on tty2. At one point getting stuck and having to reboot. In most cases was able to leave the new session with 'Ctrl+Alt+F1'.

This was tested on both my Kubuntu 20.04. An a new Kubuntu 20.10 in a VM. At some point in 20.04 a 'Switch User' icon suddenly appeared in the application launcher that wasn't there before. Still not sure what caused that.

I will explore KDE with other distros to determine if this is a Kubuntu problem or a KDE problem.

My Opinion:

This would would be a definite deal breaker for a multi user machine. I have been using Kubuntu for many years now as a sole user and love it. But for multiple users I feel it would be complete trash with the current default installation.