Thanks, it’s working now.
It turns out SDDM’s auto login was the problem - not sure if it was all along or in addition to that regression (I should’ve checked earlier logs more carefully)
Sample log output
I noticed this in /var/log/Xorg.0.log:
[ 483.780] (EE) Failed to open authorization file "/var/run/sddm/{5cd37d36-6e3a-4fc5-b255-2faeb13837d9}": No such file or directory
And systemctl status sddm:
Nov 19 12:25:42 sddm-helper[1237]: pam_env(sddm-autologin:session): deprecated reading of user environment enabled
Nov 19 12:25:42 sddm-helper[1237]: pam_kwallet5(sddm-autologin:session): pam_kwallet5: pam_sm_open_session
Nov 19 12:25:42 sddm-helper[1237]: Starting: "/usr/share/sddm/scripts/wayland-session /usr/bin/startplasma-x11"
Nov 19 12:25:42 sddm[731]: Session started
Nov 19 12:25:42 sddm-helper[1237]: [PAM] Closing session
Nov 19 12:25:42 sddm-helper[1237]: pam_unix(sddm-autologin:session): session closed for user luke
Nov 19 12:25:42 sddm-helper[1237]: pam_kwallet5(sddm-autologin:session): pam_kwallet5: pam_sm_close_session
Nov 19 12:25:42 sddm-helper[1237]: pam_kwallet5(sddm-autologin:setcred): pam_kwallet5: pam_sm_setcred
Nov 19 12:25:42 sddm-helper[1237]: [PAM] Ended.
Nov 19 12:25:42 sddm[731]: Auth: sddm-helper exited with 1
I had some .pacsave and .pacnew files I missed from previous upgrades too, one was related to PAM, but ultimately it was disabling auto login (while sddm was downgraded) and clicking the “Sync” settings button that fixed it. Re-enabling autologin works too.