[Gaming Mode - Steam Machine] Full system crash followed by Wi-Fi failure after automatic reboot

Your system information

• Steam Beta Branch: Steam Deck Stable

• SteamOS version: 3.8.16 Build: 20260716.1

• Steam client version: 1788652215

• Opted into Steam client beta?: No

• Opted into SteamOS beta?: No

• Have you checked for updates in Settings > System?: Yes

• Steam Client Build Date: Tue, Sep 1, 2026 3:03 PM UTC -05:00

• Steam Web Build Date: Sat, Sep 5, 2026 7:13 PM UTC -05:00

• Steam API Version: SteamClient023

• Steam ID: 76561198044943844

• Steam profile: https://steamcommunity.com/id/ADSthisDev/

I also submitted a Steam System Report after the incident (and manual reboot) in an attempt to preserve diagnostic information that may help Valve investigate the crash.

Please describe your issue in as much detail as possible:

While playing an unreleased game during a closed network test on my Steam Machine, the entire system unexpectedly crashed and automatically rebooted itself.

I am intentionally not naming the game publicly because this occurred while I was participating in a closed network test. I can provide the exact game and additional information privately to Valve if needed.

After the automatic reboot, SteamOS returned normally, but Wi-Fi was no longer working correctly. The Wi-Fi adapter still appeared to be enabled, but no wireless networks were shown.

I first tried turning the Wi-Fi adapter off and back on, but that did not restore the available networks.

I then performed a full reboot of the Steam Machine with the Wi-Fi adapter left enabled. After that manual reboot, Wi-Fi connected normally again.

• The important part is that this was not simply the game closing or crashing back to Steam. The entire Steam Machine rebooted itself, and the Wi-Fi subsystem was left in a broken state afterward until I manually rebooted the machine again.

• The crash occurred while I was using the Steam Machine's standard/default compatibility settings for the game. Afterward, I manually forced the game to use GE-Proton11-5-x86_64.

With that compatibility layer enabled, both stability and overall performance improved significantly compared with the default configuration. I have not experienced the same level of instability while using it.

I have also had what I remember being a very similar experience with Phantasy Star Online 2: New Genesis. If I am remembering correctly, under the default compatibility configuration (and a different version of proton that I don't recall) I experienced the same type of full system crash and automatic reboot while playing. After forcing a newer Proton compatibility layer (GE-Proton11-5-x86_64), PSO2: NGS became stable and worked normally for me.

Because I have now seen a similar pattern with more than one game, I am wondering whether there may be a broader compatibility issue affecting some games under the default Steam Machine compatibility configuration rather than this being isolated to one specific title.

I am not assuming that both crashes necessarily have the same underlying cause, but the improvement after forcing a newer Proton compatibility layer seemed significant enough that I wanted to include it.

Expected behavior:
A game should not cause the entire Steam Machine to crash and automatically reboot, nor should something cause the Wi-Fi adapter to crash causing a system failure that forces the Steam Machine to self-reboot. If the system does reboot unexpectedly, the Wi-Fi adapter should also initialize normally afterward and available wireless networks should still appear.

Actual behavior:
The entire Steam Machine crashed and automatically rebooted while the game was running under the standard/default compatibility configuration. After the automatic reboot, Wi-Fi showed no available wireless networks even though the adapter was enabled. Turning Wi-Fi off and back on did not restore the networks. A second, manually initiated full reboot restored Wi-Fi.

Afterward, forcing GE-Proton11-5-x86_64 substantially improved both game stability and performance.

Steps for reproducing this issue:

I do not yet have a guaranteed reproduction method, but this is what happened:

1. Launch a game that isn't native (like PSO2: NGS or the game I'm testing) on the Steam Machine using the standard/default compatibility configuration.
2. Play the game normally.
3. During gameplay, the entire Steam Machine may unexpectedly crash and automatically reboot.
4. After SteamOS starts again, Wi-Fi may show no available wireless networks even though the Wi-Fi adapter is enabled.
5. Turning the Wi-Fi adapter off and back on did not restore the available networks in my case.
6. Performing another full reboot of the Steam Machine restored normal Wi-Fi operation.
7. Afterward, force the game to use GE-Proton11-5-x86_64.
8. With that compatibility layer forced, stability and performance improved significantly in my experience.

Start with the Steam System Report submitted after the crash and compare it with the reported sequence: a full system reboot during gameplay, followed by missing Wi-Fi networks until a second reboot. Review the default compatibility configuration and the GE-Proton11-5-x86_64 result, then confirm the issue with a reproducible game and logs showing both the crash and Wi-Fi recovery behavior.