Describe the bug
SteamVR fails to start on SteamOS 3.8.25, SteamVR Beta 2.17.7; Shared IPC Compositor Init Failed (303)

To Reproduce
Steps to reproduce the behavior:

1. Go to SteamOS Desktop Mode
2. Click on SteamVR
3. Click Launch
4. SteamVR launches, displays window, then closes, and cannot be closed except via System Monitor.

Expected behavior
Click Launch, SteamVR runs.

System Information (please complete the following information):

• Steam client version (build number or date): 1787097529
• SteamVR version: 2.17.7
• Distribution (e.g. Ubuntu): SteamOS
• Steam runtime diagnostics:

steam-runtime-diagnostics.json

• Steam and SteamVR logs:

steam-logs.tar.gz

• Minidumps:

steam-minidumps.tar.gz

Operating System: SteamOS 3.8.25 Build: 20260807.2
KDE Plasma Version: 6.4.3
KDE Frameworks Version: 6.16.0
Qt Version: 6.9.1
Kernel Version: 6.18.42-valve2-1-neptune-618-gaf6356cf2488 (64-bit)
Graphics Platform: Wayland
Partition: B
Processors: 16 × AMD Ryzen 7 9800X3D 8-Core Processor
Memory: 128 GiB of RAM (123.4 GiB usable)
Graphics Processor 1: AMD Radeon RX 9070 XT
Graphics Processor 2: AMD Ryzen 7 9800X3D 8-Core Processor
Manufacturer: Micro-Star International Co., Ltd.
Product Name: MS-7E61
System Version: 1.0

Steam Beta Branch: Steam Deck Beta
Steam Version: 1787097529
Steam Client Build Date: Tue, Aug 18, 2026 16:29 UTC -08:00
Steam Web Build Date: Tue, Aug 18, 2026 15:32 UTC -08:00
Steam API Version: SteamClient023

Additional context
This occurs with the headset plugged in and unplugged, on the latest SteamOS beta/preview and SteamVR beta. This is a custom Steam Machine with all AMD components. Additionally, sometimes other applications erroneously trigger SteamVR (Eve Online, for example, triggers the VR runtime).

Headset is a Valve Index, all components plugged directly into MB.