After a full reboot, the login prompt is shown. After login, it does something and returns to the login prompt, where I need to login again and finally, I see the desktop.
This affects Teamviewer as well. Teamviewer does not connect properly until after the first login occurs. Removing Teamviewer does not help the double login problem. Teamviewer requires LightDM for reliable operation on Linux.
This is not the first time I have seen this happen. In the past it happened with CentOS and GNOME, I switched DM’s to LightDM and problem went away. This time I started with Ubuntu Server, added Desktop and went to LightDM and prepared the linux environment (building an appliance). After running updates, reboots and testing, I ran updates and this started happening.
I have ripped out the desktop environment, both lightDM and gdm3 and re-installed the desktop environment, no success. I removed with apt purge.