If you're using GNOME then choose the user and when you're on the password screen there will be a "gear icon"
in the lower right. Click on it before you enter the password and you can select Gnome on X11.
Thanks Ed, that did the trick. The GNOME selector gave me three choices, Gnome, Gnome Classic, and Gnome Wayland. The first choice, Gnome appears to be the X11 version.