### System details

- Omarchy 4.0.4-1; Hyprland 0.56.2-2 (Wayland)
- Kernel: 7.2.5-3-omarchy
- CPU: AMD Ryzen 9 7950X3D; motherboard: ASUS TUF GAMING X670E-PLUS WIFI
- GPU driving both monitors: NVIDIA GeForce RTX 5080 (MSI), nvidia-open-dkms / nvidia-utils 610.57.04-1
- Two LG UltraGear DisplayPort monitors, both 2560×1440 at 120 Hz, scale 1, VRR off
- Left: DP-2, portrait (transform 1), position 0x0. Right: DP-1, landscape, position 1440x0

### What's wrong?

The left monitor intermittently goes black and comes back after sleep/wake, while the right monitor continues working normally. The desktop remains usable on the right display. Expected: both displays should recover and remain stable after waking.

The sleep/wake association is based on my observations; the exact trigger has not yet been isolated between system suspend/resume and display idle/DPMS wake. The available current-boot journal does not record an actual suspend/resume cycle, and there are no recorded NVIDIA Xid errors in the logs checked. I am reporting the observed behavior, not a confirmed root cause in Omarchy or NVIDIA.

### Steps associated with the issue

1. Use the dual-monitor configuration below at 120 Hz.
2. Allow the system/displays to sleep, then wake them.
3. The left display can begin repeatedly blacking out and returning; the right stays normal. This is intermittent, not reproduced on every wake.

```lua
hl.monitor({ output = "DP-2", mode = "2560x1440@120", position = "0x0", scale = 1, transform = 1 })
hl.monitor({ output = "DP-1", mode = "2560x1440@120", position = "1440x0", scale = 1 })
```

### Refresh-rate workaround

Switching the left display from 120 Hz to 60 Hz and back to 120 Hz appeared to clear the blackouts on the previous occurrence. A cable reseat also happened during that earlier troubleshooting, so its effect was not isolated. I suspect the refresh-rate reset was the useful action rather than the cable reseat.

On October 4, the following reset was applied again without unplugging either cable, and Hyprland verified the intermediate ~59.951 Hz and restored ~119.998 Hz states. Whether this latest reset resolves the blackouts long-term remains to be confirmed.

```bash
hyprctl eval 'hl.monitor({ output = "DP-2", mode = "2560x1440@60", position = "0x0", scale = 1, transform = 1 })'
# Verify the 60 Hz mode has applied before restoring:
hyprctl monitors -j
hyprctl eval 'hl.monitor({ output = "DP-2", mode = "2560x1440@120", position = "0x0", scale = 1, transform = 1 })'
```

The right display stayed at 120 Hz throughout; resolution, rotation, and layout were preserved. No persistent configuration change was needed.

### Diagnostic details

- `/sys/power/mem_sleep`: `s2idle [deep]`
- NVIDIA: `PreserveVideoMemoryAllocations: 1`, `EnableS0ixPowerManagement: 0`, `TemporaryFilePath: "/var/tmp"`
- `nvidia-suspend.service`, `nvidia-resume.service`, and `nvidia-hibernate.service`: all reported `disabled` by `systemctl is-enabled`. This is enablement state, not proof they did or did not run during a previous sleep.
- Before the reset, Hyprland reported both displays enabled and `dpmsStatus: true` despite the reported left-display blackouts.
- Omarchy shell idle settings: screensaver 150 seconds, lock 300 seconds.
- `omarchy-debug --no-sudo --print` was collected locally; relevant hardware/software details are included above. No video capture of the physical blackouts is available.

Possibly related: #12129 and #13251. Those reports involve laptop panels that remain dark; this report involves one of two external desktop displays intermittently blanking, with a refresh-rate reset workaround. I have not established a shared root cause.