display manager craches with two monitors

[mahesh]

Hi,

I have used standard Ubuntu LTSs for many years, and recently (due to an SSD change) I decided to give 23.04 a try. I have an intel i7 based laptop (no extra video card, the build-in intel video driver is used), attached to an external monitor via HDMI. At home I use exclusively the external screen (i.e. the laptop screen is turned of via control panel); this combo has worked like a charm for many years with different LTSs.
Now this setting produces random logouts when the external monitor switches off due to inactivity. When I try to wake up the laptop (e.g. by moving the mouse), sometimes the login screen on the laptop monitor gets activated instead of the external monitor, I need to log in again and restart all my software once again. The error appears really randomly; sometimes the machine wakes up after hours of inactivity without issues, sometimes 3 minutes is enough for a crash. This is very annoying, I started wondering about reinstalling 22.04 LTS once again. Any advice on this?