scpy screen capture causes glitches on external monitor

[rszyma]

1. Open OBS
2. In OBS select "Wayland output(scpy)"
3. Create a new window (terminal or sth) and start moving it around.
4. Observe green glitchy artifacts appearing over updated areas. On the recording the glitches are not being captured, and instead frames are being dropped when the glitches appeared.

glitchy_scpy_recording_2025-07-25.18-31-16.mp4

Relevant config entries:

monitor = eDP-1,disable
monitorv2 {
  output = HDMI-A-1
  mode = 1920x1080@180
  position = 0x0
  scale = 1
  bitdepth = 8
}
render { 
  new_render_scheduling = true
}

hyprctl version

Hyprland 0.49.0 built from branch  at commit b5433bb75324a95dd27eb5492141565466c2cdd6  ().
Date: 2025-07-10
Tag: v0.49.0, commits: 6265
built against:
 aquamarine 0.9.0
 hyprlang 0.6.3
 hyprutils 0.8.1
 hyprcursor 0.1.12
 hyprgraphics 0.1.4


no flags were set

Other relevant info:

• It only happens on external display. It doesn't happen on eDP-1.
• Selecting dmabuf in OBS doesn't work at all (it crashes OBS).
• wl-screenrec works without issues. Looking at its verbose logs it uses dmabuf (zwp_linux_dmabuf_v1). Not sure why it doesn't work in OBS then.
• changing vfr, vrr makes no difference wrt this issue.

[rszyma]

After setting new_render_scheduling to false glitches no longer appear.