I do not use login manager but did you try to put "needs_root_rights = yes" in /etc/x11/Xwrapper.config to fix root/user permission arizing with the new xorg-server version ?
I do not use login manager but did you try to put "needs_root_rights = yes" in /etc/x11/Xwrapper.config to fix root/user permission arizing with the new xorg-server version ?