VR: Controllers not working due to "wrong" appname?

[Spacefish]

When running VR games via Proton which use the SteamVR API all the buttons and thumbsticks as well as the trigger does not seem to work.
Games that support OpenXR as well as SteamVR work fine via OpenXR (for example VTOL VR).
I remember running VRChat (which uses SteamVR / OpenVR APIs) under Linux a year ago and it worked fine, but now it´s broken.

When you look at the input mapping in the steam VR overlay, the current Game is shown as "WINEOPENXR TEST INSTANCE" and no mapping is found.

So i guess the main issue is the steam VR compositor not being able to detect the current game and so not loading any input mappings for it.

The OpenXR wine layer seems to set this "wineopenxr test instance" name as executable name and engine name here:
https://github.com/ValveSoftware/Proton/blob/proton_9.0/wineopenxr/openxr.c#L501

It was moved arround aprox. a year ago as well:
273c5c2#diff-97055500218f958f1a373b59551dcbe4519e5c1a72c0a7cc79d16fc7064ad4b7R441

The function seem to be called here:

Proton/steam_helper/steam.cpp

Line 901 in f1933d3

if ((hwineopenxr = LoadLibraryA("wineopenxr.dll")))

wonder if this is the root cause / the reason why Steam is unabled to load an input mapping for the VR Controllers, as it does look at the game / engine name supplied via XrInstanceCreateInfo but that is static?

If i launch the game with Proton 7.x the game name is correctly displayed in the controller mappings, however the game crashes with Proton 7.x ... so i don´t know wether input works with proton 7.x

i can´t create a custom controller binding as well, as once i click on "create binding" i am redirected to a black screen without any possibilty for input..

Environment info:

• Ubuntu 25.04 with Wayland / KDE (Kernel 6.12)
• Valve Index
• Latest Proton Experimental
• SteamVR 2.9.6