See if this System76 guide is of help (it uses same commands as you would find in Zorin):
Setup facial recognition for authentication (howdy). - System76 Support
I would also see if you have same issue in X11 (Zorin on xorg) as the default compositor is set to Wayland (Zorin Desktop) by default. Before you enter your password, select your username at login and a cog should appear lower right - change this to 'Zorin on xorg' from 'Zorin Desktop'.