SDDM "login failed" after migrating to new hard drive (Debian Testing + KDE)

My laptop came with a 1TB hard drive, but I recently switched to a 512GB SSD to improve speed. To do that, I dd'd the EFI partition and cp'd the root and home partitions. I think I messed that up at some point with permissions because after doing so, I had to go through and fix permissions for a few of my programs to work, but I managed to figure out the problem for most of those. I'm still having issues with SDDM, though. It'll allow me to log in right after booting, but if I try to log in after the computer has gone to sleep, it will give me the "login failed" message (even with the correct password and user). I have to reboot my laptop if it has gone to sleep so that I can log in normally. I tried reinstalling SDDM, libpam0g, and packages to do with kwallet, but that has not helped. Any ideas for what might be going wrong or what I could do to figure that out?

Can you switch to a console terminal (Ctrl+Alt+F1) and login there? If so, can you check dmesg or other logs to see if SDDM is giving a error?
Maybe try a different display manager and see if it has the same issue.

Originally Posted by uteck Can you switch to a console terminal (Ctrl+Alt+F1) and login there? If so, can you check dmesg or other logs to see if SDDM is giving a error? Maybe try a different display manager and see if it has the same issue.

Yes, I can still log into TTYs, the only place where login fails is SDDM after suspending/sleeping to get into my X session. There is no error given by SDDM that I can find in dmesg after login fails, but systemd is periodically sending this message to dmesg, which is apparently related to KDE screen locking (https://bbs.archlinux.org/viewtopic.php?id=258138; the solution there is unfortunately not helpful for me because this is not caused by Nvidia drivers (which I do not use)):

[   73.499494] systemd-xdg-autostart-generator[2960]: Not generating service for XDG autostart app-powerdevil-autostart.service, only Type=Application is supported.
[   73.499573] systemd-xdg-autostart-generator[2960]: kde-systemd-start-condition not found: No such file or directory
[   73.499634] systemd-xdg-autostart-generator[2960]: Not generating service for XDG autostart app-at\x2dspi\x2ddbus\x2dbus-autostart.service, startup phases are not supported.
[   73.499662] systemd-xdg-autostart-generator[2960]: kde-systemd-start-condition not found: No such file or directory
[   73.499680] systemd-xdg-autostart-generator[2960]: Not generating service for XDG autostart app-pulseaudio-autostart.service, startup phases are not supported.
[   73.499848] systemd-xdg-autostart-generator[2960]: kde-systemd-start-condition not found: No such file or directory
[   73.499907] systemd-xdg-autostart-generator[2960]: kde-systemd-start-condition not found: No such file or directory
[   73.499941] systemd-xdg-autostart-generator[2960]: gnome-systemd-autostart-condition not found: No such file or directory
[   73.499992] systemd-xdg-autostart-generator[2960]: Not generating service for XDG autostart app-xdg\x2duser\x2ddirs-autostart.service, startup phases are not supported.

That's the only thing related to SDDM or KDE in dmesg. The linked Arch forum thread led me to another thread indicating that problem might trace back to kscreenlocker, so I reinstalled all packages for kscreenlocker with apt. That did not fix the problem.

I'll check if LightDM also does this or if it's an SDDM issue in a bit.

I installed lightdm and set it to my default and it does load on initial boot, but if I close the laptop lid and open it again, it gives me the same SDDM login as before...
I can use sudo loginctl unlock-session to get me back into X, but I can't log in from the GUI. Bizarre.