DirectInput hid_joystick_enum_device fails to enumerate gamepad, breaking XInput entirely — reproducible standalone with joy.cpl, no Steam involved

System: CachyOS (Arch-based), kernel 7.2.6-1-cachyos, Hyprland (Wayland).
Controller: Generic gamepad presenting as 054c:05c5 (Sony DualShock 4 spoof) in one mode, 4131:3519 in another (force-bound to the xpad kernel driver, since it's not in xpad's default ID table).
Proton version: Proton 11.0-2, Proton - Experimental
Minimal reproduction - no Steam client, no specific game required:

1. Quit Steam completely (verified via pgrep, zero Steam processes).
2. Create a fresh Wine prefix using Proton's own bundled wine directly: WINEPREFIX=/path/to/fresh/prefix "/files/bin/wine" wineboot -i
3. Launch Proton's own controller diagnostic tool: WINEDEBUG=+xinput,+dinput,+joystick WINEPREFIX=/path/to/fresh/prefix "/files/bin/wine" control joy.cpl
4. Joysticks tab correctly lists the controller under "Connected (XInput devices)". "Enable SDL" is checked by default.
5. XInput tab's live test panel shows: "No user detected on slot #1... make sure your gamepad is plugged in, and not overridden for DInput in the Joysticks tab."
6. The WINEDEBUG log shows: warn:dinput:hid_joystick_enum_device index 0 not found, the trigger for the failed detection.

This reproduces with zero Steam involvement — no client running, no game, no Steamworks — ruling out Steam-side interference as the cause (see ValveSoftware/steam-for-linux#12231, closed by its author after concluding an identically-shaped symptom was actually this exact Proton-side bug).

Also reproduced in-game across three separate titles (Steamworks and non-Steamworks) and three different Proton builds (Proton - Experimental, Proton 11.0-2, GE-Proton11-7), so it isn't tied to one specific build either.

Intermittency note: oddly, the same setup can work correctly for weeks, then fail like this across every configuration for days, then recover with no changes — happy to provide more detail if useful for narrowing this down.

Start by reproducing the failure with Proton's bundled wine and control joy.cpl, using WINEDEBUG=+xinput,+dinput,+joystick. Trace the hid_joystick_enum_device index 0 not found warning and compare the DirectInput and XInput enumeration paths. Done means the gamepad is detected by XInput and the live test panel recognizes it reliably.