Can you print the contents of these files?

/etc/sddm.conf
/etc/sddm.conf.d/kde_settings.conf

(In reply to Nate Graham from comment #1)
> Can you print the contents of these files?
> 
> /etc/sddm.conf
> /etc/sddm.conf.d/kde_settings.conf

___________________________________________
/etc/sddm.conf
-------------------------------------------
[General]
InputMethod=qtvirtualkeyboard

[Theme]
DisableAvatarsThreshold=7
EnableAvatars=true
FacesDir=/usr/share/sddm/faces
ThemeDir=/usr/share/sddm/themes

[Users]
DefaultPath=/usr/local/sbin:/usr/local/bin:/usr/bin
HideShells=
HideUsers=
RememberLastSession=true
RememberLastUser=true
ReuseSession=true

[Wayland]
EnableHiDPI=false
SessionCommand=/usr/share/sddm/scripts/wayland-session
SessionDir=/usr/share/wayland-sessions
SessionLogFile=.local/share/sddm/wayland-session.log

[X11]
DisplayCommand=/usr/share/sddm/scripts/Xsetup
DisplayStopCommand=/usr/share/sddm/scripts/Xstop
EnableHiDPI=false
MinimumVT=1
ServerPath=/usr/bin/X
SessionCommand=/usr/share/sddm/scripts/Xsession
SessionDir=/usr/share/xsessions
SessionLogFile=.local/share/sddm/xorg-session.log
UserAuthFile=.Xauthority
XauthPath=/usr/bin/xauth
XephyrPath=/usr/bin/Xephyr

___________________________________________
/etc/sddm.conf.d/kde_settings.conf
-------------------------------------------
[Autologin]
Relogin=false
Session=
User=

[General]
HaltCommand=/usr/bin/systemctl poweroff
Numlock=on
RebootCommand=/usr/bin/systemctl reboot

[Theme]
Current=breeze
CursorTheme=breeze_cursors
Font=Noto Sans,9,-1,5,50,0,0,0,0,0

[Users]
MaximumUid=60000
MinimumUid=1000

[X11]
ServerArguments=-dpi 0

So sorry, I asked for the wrong data. :(

Instead can you provide the contents of /usr/share/sddm/themes/breeze/theme.conf?

Also, you should see a "background=[something]" line, where [something] is a file path. Can you tell me if that file path is the image you expect, or something else?

(In reply to Nate Graham from comment #3)
> So sorry, I asked for the wrong data. :(
> 
> Instead can you provide the contents of
> /usr/share/sddm/themes/breeze/theme.conf?
> 
> Also, you should see a "background=[something]" line, where [something] is a
> file path. Can you tell me if that file path is the image you expect, or
> something else?

"background" property in "/usr/share/sddm/themes/breeze/theme.conf" file points to the correct image. What I found is that at certain time with 5.21 I changed SDDM Breeze background then wanted to revert back to default but I didn't find how to do it, even after selecting another SDDM theme then reapply Breeze the default image never returned, so the only solution is that I downloaded 5.21 wallpaper and selected it as background using Plasma settings, that downloaded image was copied to folder "/usr/share/sddm/themes/breeze/" and a new file called "theme.conf.user" was automatically added to the same folder with property "background" set to the copied image name, so after upgrading to 5.22 the file "theme.conf.user" still overrides the default new wallpaper and there is no way to apply it using Plasma settings UI.

So you broke it while trying to work around Bug 432195. :)

I think you should just undo your handmade customizations, and we should fix Bug 432195.

(In reply to Nate Graham from comment #5)
> So you broke it while trying to work around Bug 432195. :)
> 
> I think you should just undo your handmade customizations, and we should fix
> Bug 432195.

I didn't broke it, that file that overrides default image was automatically created via Plasma settings UI and no manual customization is involved, and this problem is totally different than Bug 432195, in my case it's impossible to reset SDDM theme default wallpaper even after selecting another theme then revert it back.

Oh, this seems to have something to do with the settings cascade issue then. Semi-related to the root cause of Bug 440564.