New comment by CabrioletDiskette on void-packages repository

https://github.com/void-linux/void-packages/issues/44551#issuecomment-1609164860

Comment:
The testing I did was in a fresh install in a vm with only lightdm and xfce4. The idea behind the reinstall/remove exercise was to hope that the lightdm pkg replaces the configs with the default ones provided. Simply removing the pkg does not work as user created configs are not removed when a pkg is uninstalled. Try that out and see what happens. If that doesn't work than perhaps something else is at play that I need to replicate your problem. 

So in summary:

Super user(via sudo, su etc)

rm -r /etc/lightdm(make sure you got the right dir!)

xbps-remove -Rf lightdm lightdm-gtk3-greeter(or whatever one you have installed)

xbps-install -S lightdm lightdm-gtk3-greeter(whichever greeter you want)

Then add back the config lines you want.

Best of luck