Dear Mattias,
Thank you for the analysis. I hit this too, and GDM autologin did not work anymore [1], so users thought Debian crashed during startup. Switching to tty2 and logging in and changing the password there, fixed the issue.
I asked for a Linux PAM point release, so distributions can easily pick it up [2].
Kind regards, Paul [1]: https://gitlab.gnome.org/GNOME/gdm/-/issues/724 [2]: https://github.com/linux-pam/linux-pam/issues/367
