Monitors not detected (StarTech USB32HD2, Ubuntu 24.04)

[greengreengrassofhome]

I'm trying to connect two monitors to a laptop with an USB 3 port via a StarTech USB32HD2 adapter. The official product description claims the device only supports Windows, however some quick searching indicates others have gotten it working under Ubuntu before (see for example https://askubuntu.com/questions/1169583/how-to-use-startech-usb32hd2-with-ubuntu-18-04).

I have installed displaylink-debian, and the debug output tells me that it is up and running. However the monitors remain dark, and when I for example open Displays in the system settings, it does not show me any monitors except the built-in one.

This is the output after I ran sudo ./displaylink-debian.sh --debug for the first time:

--------------- Linux system info ----------------

Distro: Ubuntu
Release: noble
Kernel: 6.8.0-35-generic

---------------- DisplayLink info ----------------

Driver version: 1.14.4
DisplayLink service status: up and running
EVDI service version: 1.14.4

------------------ Graphics card -----------------

Vendor: amdgpu
Subsystem: [Radeon
VGA: Advanced Micro Devices, Inc. [AMD/ATI] Picasso/Raven 2 [Radeon Vega Series / Radeon Vega Mobile Series] (rev ce)
VGA (3D): 
X11 version: 21.1.12-1ubuntu1
X11 configs: /etc/X11/xorg.conf.d/20-displaylink.conf

-------------- DisplayLink xorg.conf -------------

File: /etc/X11/xorg.conf.d/20-displaylink.conf
Contents:
 Section "Device"
    Identifier "AMDGPU"
    Driver     "amdgpu"
    Option     "PageFlip" "false"
EndSection

-------------------- Monitors --------------------

Providers: number : 1
Provider 0: id: 0x53 cap: 0x9, Source Output, Sink Offload crtcs: 3 outputs: 2 associated providers: 0 name:AMD Radeon Vega 3 Graphics @ pci:0000:03:00.0

And this is the output after I removed the /etc/X11/xorg.conf.d/20-displaylink.conf file according to the post installation guide:

--------------- Linux system info ----------------

Distro: Ubuntu
Release: noble
Kernel: 6.8.0-35-generic

---------------- DisplayLink info ----------------

Driver version: 1.14.4
DisplayLink service status: up and running
EVDI service version: 1.14.4

------------------ Graphics card -----------------

Vendor: amdgpu
Subsystem: [Radeon
VGA: Advanced Micro Devices, Inc. [AMD/ATI] Picasso/Raven 2 [Radeon Vega Series / Radeon Vega Mobile Series] (rev ce)
VGA (3D): 
X11 version: 21.1.12-1ubuntu1

-------------- DisplayLink xorg.conf -------------

File: /etc/X11/xorg.conf.d/20-displaylink.conf
cat: /etc/X11/xorg.conf.d/20-displaylink.conf: No such file or directory
Contents:

-------------------- Monitors --------------------

Providers: number : 5
Provider 0: id: 0x53 cap: 0x9, Source Output, Sink Offload crtcs: 3 outputs: 2 associated providers: 4 name:AMD Radeon Vega 3 Graphics @ pci:0000:03:00.0
Provider 1: id: 0xe0 cap: 0x2, Sink Output crtcs: 1 outputs: 1 associated providers: 1 name:modesetting
Provider 2: id: 0xbf cap: 0x2, Sink Output crtcs: 1 outputs: 1 associated providers: 1 name:modesetting
Provider 3: id: 0x9e cap: 0x2, Sink Output crtcs: 1 outputs: 1 associated providers: 1 name:modesetting
Provider 4: id: 0x7d cap: 0x2, Sink Output crtcs: 1 outputs: 1 associated providers: 1 name:modesetting

I've also attached the output from dmesg and the relevant info for the adapter from lsusb.

I've read the post installation and troubleshooting guides, and don't know where to look next. Any pointers would be much appreciated.

[greengreengrassofhome]

Looking at /var/log/syslog , I see a few instances of the following:

/usr/libexec/gdm-x-session[2166]: MESA-LOADER: failed to open evdi: /usr/lib/dri/evdi_dri.so: cannot open shared object file: No such file or directory (search paths /usr/lib/x86_64-linux-gnu/dri:\$${ORIGIN}/dri:/usr/lib/dri, suffix _dri)

May that be relevant?

Additionally, I installed Ubuntu 22.04 alongside 24.04 and did the whole procedure again, with the exact same result (including the error messages mentioned above).