Latest official driver not working on Kubuntu 24.04.01 LTS w/XOrg

[psypete]

I have Kubuntu 24.04 on a new Thinkpad. I use GDM as my login manager, and KDE Plasma as my desktop.

With the stock evdi-dkms drivers, I am able to use my Dell D6000 displaylink with an external monitor, both at GDM login screen, and Plasma X11/XOrg.

When I install the official displaylink drivers (via the Synaptic apt repository), my external monitor works at the GDM login screen. But login to Plasma XOrg, and the monitor does not show up. xrandr does not show it, the Plasma display manager does not show it. If I hit my laptop 'display switch' keyboard key, I can see the options to switch monitors, but clicking on them does nothing. Rebooted, no change.

I uninstalled the official displaylink drivers and reinstalled the stock evdi-dkms package, and everything works again.
So I will keep using the stock Kubuntu drivers for now, but would like to use the official drivers.

(I am not using Wayland, and won't use it, until they pry XOrg out of my cold dead hands)