USB 2 UDL DisplayLink monitor black screen

[0xfMel]

Hyprland version

Hyprland 0.52.0 built from branch main at commit abb2f7e clean (renderer: fix render_unfocused).
Date: Fri Nov 21 18:48:45 2025
Tag: v0.52.0-80-gabb2f7ee6, commits: 6639

Libraries:
Hyprgraphics: built against 0.4.0, system has 0.4.0
Hyprutils: built against 0.10.2, system has 0.10.2
Hyprcursor: built against 0.1.13, system has 0.1.13
Hyprlang: built against 0.6.6, system has 0.6.6
Aquamarine: built against 0.9.5, system has 0.9.5

no flags were set

(issue is the same on latest release build)

Describe the bug

I have a USB 2 DisplayPort monitor using just the udl driver (no evdi/displayport drivers). The monitor appears as VGA-1 through hypctl monitors, with the correct dimensions and mode etc, but shows a black screen.
I've also tested with plasma wayland to ensure its not a driver/hardware issue and its working there.
Trying to use evdi/displayport drivers makes no difference.

Logs:
hyprland.log

System info and config

systeminfo.txt