Failed to map scanout buffer 2 monitors

[rowanG077]

• Linux distribution and its version: NixOS unstable
• Linux kernel version 6.5.0
• Xorg version (if used): Using wayland
• Desktop environment in use: Hyprland
• two 2560x1440 monitors

I'm running hyprland on Aarch64 with this adapter: https://www.startech.com/en-nl/display-video-adapters/usb32dp24k60

When in use with one monitor it works without issues. However if I plug in the second monitor the monitor is "recognized" in hyprland but the monitor itself does not display anything.

Looking into dmesg I can see spam of

[18033.491780] evdi: [E] evdi_painter_grabpix_ioctl:1076 Failed to map scanout buffer

messages. Sometimes a message

[18033.491780] evdi: [E] evdi_cursor_set:131 Failed to map cursor.

appears. But this is much, much rarer. Without the second monitor attached dmesg is clean.

Does anyone have a clue what is going wrong here? Is something misconfigured on my side?