I have an installation that is running the 5.8 kernel and when I upgraded to 5.10 I found that lightdm is not able to start up. If I change the boot parameters to use systemd.unit=multi-user.target I can successfully start up by running the lightdm unit or by running startx. I also tried an older kernel (5.4) with the same results.
I’ve checked the lightdm logs and they don’t show any obvious errors nor do the Xorg logs.
I’ve seen a lot of reference to issues with nvidia drivers but I don’t have any installed as my laptop has intel graphics only.
It seems like the issue must be related to something being done differently in my 5.8 kernel setup but I don’t know what to look for.