Your system information

• Steam client version (build number or date):

  • Default: Stable Client Wed, Jun 24, 2026 1:13 AM UTC -08:00
  • Using -steamos: Steam Deck Stable Wed, Jun 24, 2026 1:13 AM UTC -08:00

• Distribution: CachyOS (Linux 7.1.1-2-cachyos, KDE 6.7.1)

• Opted into Steam client beta?: No

• Have you checked for system updates?: Yes

• Steam Logs:

  • Default client: steam-logs-stable-client.tar.gz
  • Using -steamos: steam-logs-steam-deck-stable.tar.gz

• GPU: AMD (7900XTX)

Please describe your issue in as much detail as possible:

Custom proton forks such as Proton-CachyOS, Proton-GE and Proton-EM offer the variable PROTON_ENABLE_WAYLAND=1 to enable the experimental wine wayland driver. It currently breaks some things including steam input which is needed for certain games such as MH:Wilds as they provide no alternative API.

Until very recently there was a dirty workaround/hack: By launching steam with the launch argument -steamos (formerly -steamos3) steam input somehow became functional. This allowed me to play those games with my controller while at the same time enjoying the benefits of running the game natively on wayland such as better frame pacing and HDR.

But since the last client update this hack does not work anymore. This applies to all client versions (including the beta and the experimental SteamRT3 client).

As an AMD user the obvious solution would be to use gamescope to make things like HDR work (which got thankfully fixed in KDE 6.7.1) but despite this I still consider it a slight downgrade (as it's still running through xwayland). For Nvidia users there seems to be no good alternative.

And the previous solution was already sub-optimal as -steamos is certainly not intended for this use case.

I'm assuming but I imagine there was some fix/hack in place that allowed steam input to work previously. Would it be possible to offer that one to the people that like running their games with PROTON_ENABLE_WAYLAND=1? Seems like a small but meaningful temporary band-aid solution until wayland is fully functional (which will probably take a while).

Controller used: Guiltkit KingKong 2 Pro Controller (emulates itself as a Xbox 360 controller). Tested both wireless and wired.

Steps for reproducing this issue:

1. Preparation: Install Proton-CachyOS (I tested with the latest nightly version but the latest stable has the same outcome)
2. Open steam through the terminal using the -steamos argument
3. Set Proton-CachyOS as the compatibility tool under properties > compatibility.
4. Launch the game with the arguments below (note: I also used game-performance, mangohud and PROTON_FSR4_UPGRADE=1 in my testing with no impact on the outcome)
5. Observed behavior: Game runs, Keyboard and Mouse input work but controller is not working (despite being recognized by steam)
6. Change launch arguments to use gamescope instead -> Controller input and HDR are working although game is still running through xwayland.

Launch arguments (MH:Wilds)

Using wine wayland driver: PROTON_ENABLE_WAYLAND=1 %command% /WineDetectionEnabled:False
Using gamescope (currently working solution): gamescope -w 3840 -h 2160 -W 3840 -H 2160 -r 240 -f --hdr-enabled -- %command% /WineDetectionEnabled:False