Your system information

• Steam client version (build number or date): 1785799196
• Distribution (e.g. Ubuntu): CachyOS/Arch
• Opted into Steam client beta?: [Yes/No] No (But have in the past, makes no difference)
• Have you checked for system updates?: [Yes/No] Yes
• GPU: RTX 4070 SUPER (Nvidia-610-43-03)
• Steam Logs: steam-logs.tar.gz

Please describe your issue in as much detail as possible:

I received the brand new controller in late May and I started trying to use it on my desktop here which is running CachyOS and using Niri as my Window Manager.

I first tried this in Metal Gear Solid Delta: Snake Eater and noticed no controller inputs were being received.
My keyboard and mouse still worked and I could press the Steam button on the controller and navigate the Big Picture UI, but the game does not receive any gamepad inputs
I then tried Metal Gear Solid Master Collection Vol. 1 and my controller worked flawlessly

If I remap the controller to use KBM inputs (i.e. mouse on trackpad), this works and I can freely use the controller. So this is exclusively a problem with the game not receiving gamepad inputs.

Games Tested

• Metal Gear Solid Delta Snake Eater (No Input)
• Metal Gear Solid Master Collection Vol 1 (Input detected)
• Hollow Knight Silksong (Input detected)
• Blue Prince (No Input)
• Balatro (No Input)
• Warhammer 40,000 Space Marine 2 (No Input)

Things I have tried

1. Contacting Steam Support (They referred me here) Ticket HT-MF2Q-J56W-R673
2. USB vs Puck vs Bluetooth
3. Using the launch option PROTON_ENABLE_WAYLAND=1
4. Following the advice in this issue
5. Switching to Proton Experimental
6. Switching to GE-Proton
7. Switching to Proton 9.0 THIS IS THE ONLY THING THAT WORKS
8. Switching to KDE and GNOME (No difference)

Steps for reproducing this issue:

1. Setup controller and update everything on Linux using Niri (A wayland WM)
2. Attempt to launch a steam game on steam that only supports traditional gamepads (Balatro, Blue Prince)
3. Try to use any gamepad inputs

I am suspecting this is some sort of issue with SDL gamepad input passthrough? Maybe something to do with Wayland? I am truly not sure anymore. I've exhausted everything and would love any help that can be provided.