[12:24] <dreamon> hello. what is the default display manager for xfce. I installed lightdm and having trouble with it. how can I change back to its default.
[12:25] <diogenes_> dreamon, it depends on the distro, display managers are 3rd party and usually it's lightdm.
[12:30] <dreamon> diogenes_, ist ubuntu. think xubuntu 20.04.2. it have issue by locking screen. after locking I wake him up. it shows me normal desktop, like it runs. but I cannot interact with it. login screen is not visible, but after typing password and enter its unlocked and I can use it normally. 
[12:33] <diogenes_> dreamon, try this:
[12:33] <diogenes_> !acpi_osi
[12:37] <dreamon> diogenes_, Thanks.. will give it a try