Rollback from Bazzite 44 testing to 43 breaks gamescope (gamemode) on gnome deck distro

[Cruellest]

Describe the bug

After rolling back from bazzite-deck-gnome:testing (v44) to bazzite-deck-gnome:stable (v43), Gaming Mode became inaccessible. The system always booted into Desktop (GNOME) instead of Gaming Mode, and the "Return to Gaming Mode" shortcut caused the screen to flash and return to Desktop.

Symptoms:

• Every reboot landed in Desktop GNOME instead of Gaming Mode
• "Return to Gaming Mode" shortcut failed (screen flashed and returned to Desktop)
• steamos-session-select gamescope followed by systemctl reboot did not change behavior
• No session-switching attempt worked
• hhd.service was active and healthy
• gamescope binary worked perfectly when tested manually
• Steam Big Picture Mode worked normally on Desktop
• rpm-ostree status confirmed system was on latest stable (v43.20260420)

What did you expect to happen?

When booting device, it automatically launches in gamemode, and on desktop mode (GNOME) when clicking on the "Return to gamemode" button it correctly boots on gamemode

Session Logs

Not sending full pastebin because already fixed on my device but here is the logs of when i was debugging

Generated logs when debugging:


journalctl -b 0 | grep -iE "gamescope-session|steamos-session|gdm" | tail -n 30

jun 06 13:32:02 dbus-broker-launch[1209]: Looking up NSS group entry for 'gdm'...

jun 06 13:32:02  dbus-broker-launch[1209]: NSS returned NAME 'gdm' and GID '42'

jun 06 13:32:10  gnome-shell[2572]: Registering session with GDM

jun 06 13:32:10  gnome-shell[2572]: Error registering session with GDM: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name is not activatable

jun 06 13:33:30  gnome-shell[8138]: Registering session with GDM

jun 06 13:33:30  gnome-shell[8138]: Error registering session with GDM: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name is not activatable

jun 06 13:34:29 gnome-shell[14500]: Registering session with GDM

jun 06 13:34:29 gnome-shell[14500]: Error registering session with GDM: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name is not activatable 


journalctl -b 0 -u sddm --no-pager | tail -n 40
un 06 14:47:15 systemd[1]: Started sddm.service - Simple Desktop Display Manager.
jun 06 14:47:15 sddm-helper[1956]: Detected locale "C" with character encoding "ANSI_X3.4-1968", which is not UTF-8.
                                                  Qt depends on a UTF-8 locale, and has switched to "C.UTF-8" instead.
                                                  If this causes problems, reconfigure your locale. See the locale(1) manual
                                                  for more information.
jun 06 14:47:15 sddm-helper[1956]: pam_unix(sddm-autologin:session): session opened for user $USER(uid=1000) by $USER(uid=0)
jun 06 14:47:15 sddm-helper[1956]: gkr-pam: gnome-keyring-daemon started properly
jun 06 14:47:15 sddm-helper[1956]: Starting Wayland user session: "/etc/sddm/wayland-session" "/usr/bin/gnome-session"

Hardware

Hardware: ASUS ROG Ally (Ryzen Z1 Extreme)
Image: bazzite-deck-gnome:stable (v43.20260420, built 2026-04-20)
Scenario: Rollback from testing (v44) → stable (v43)

Extra information or context

Suspected Root Cause:

The file /etc/sddm.conf.d/zzt-steamos-temp-login.conf was found to persist on the system.

Suspected mechanism:

• The steamos.conf (base config) correctly specifies Session=gamescope-session.desktop
• However, zzt-steamos-temp-login.conf loads alphabetically after all other configs (prefix zzt- sorts last)
• If this file contained a Desktop session directive (e.g., Session=gnome.desktop), it would override the gamescope setting
• SDDM logs confirmed autologin was launching gnome-session instead of gamescope-session
• This suggests the temp-login file was forcing Desktop mode, but this has not been definitively verified

Solution Applied:

# 1. Examined the problematic file
cat /etc/sddm.conf.d/zzt-steamos-temp-login.conf

# 2. Moved the file out of SDDM's configuration directory
sudo mv /etc/sddm.conf.d/zzt-steamos-temp-login.conf /etc/zzt-steamos-temp-login.conf.bak

# 3. Full reboot
sudo systemctl reboot

After reboot, Gaming Mode launched successfully and has been stable.

On latest releases it is needed to move this file too:

sudo mv /etc/sddm.conf.d/zz-bazzite-autologin.conf /etc/zz-bazzite-autologin.conf.bak
sudo systemctl reboot

[Seijurou231]

Thanks, solved the issue for me as well.

[scalcam]

Ran into the same issue and your solution resolved the issue for me as well. Thanks!

[BenzLeung]

My goodness, I encountered the same issue, and it was really frustrating. However, after following the solution, it was solved perfectly, and I felt much more relieved. Thank you so much!

[Cruellest]

So guys with the latest releases it is needed to move this file too:

sudo mv /etc/sddm.conf.d/zz-bazzite-autologin.conf /etc/zz-bazzite-autologin.conf.bak
sudo systemctl reboot