Hyprland 2nd Monitor blanks out

Help
1

I have a simple Hyprland install that was working great until I updated to 24.11. Basically my 2nd monitor refuses to work. Hyprctl monitor shows the currentFormat: Invalid. It’s the same monitor as the working one with the same resolution. I tried playing with the hyprland config but nothing I do seems to work.

Gnome works fine with both monitors. No crashes from it just doesn’t work.

hyprland in my configuration.nix:

programs.hyprland = {
    enable = true;
    xwayland.enable = true;
  };

monitor section from hyprland.conf:

monitor = DP-1, 3840x2160@59.94, 0x0, 1  
monitor = DP-2, 3840x2160@59.94, 3840x0, 1

I’ve tried to set different resolutions and refresh rates, setting preferred and auto, different scaling. Nothing makes the monitor come back.

The monitor works in GDM as well but as soon as I sign into Hyprland it blanks out.

Anyone else run into this?

2

Same issue seen here on CachyOS. Two monitors, one DP one HDMI. Second monitor, if I fullscreen any application the monitor goes black, and flips off and on (or the screen turns green)

Not a NixOS related issue.