Mika, I can confirm, oddly it helped renaming /usr/share/lightdm/lightdm.conf.d/50-guest-wrapper.conf to /usr/share/lightdm/lightdm.conf.d/50-guest-wrapper.conf.bak. I am using 20.04 now.
Mika, I can confirm, oddly it helped renaming /usr/share/ lightdm/ lightdm. conf.d/ 50-guest- wrapper. conf to /usr/share/ lightdm/ lightdm. conf.d/ 50-guest- wrapper. conf.bak.
I am using 20.04 now.