DisplayLink device no longer detected on Kubuntu 20.04 with kernel 5.4.0-80
 

I have an HP USB-C Universal Dock that was previously working fine on kernel 5.4.0-77, but basically lost its DisplayLink functionality after I booted on 5.4.0-80 for the first time yesterday. Essentially it's no longer detecting the USB DisplayLink device (with vendor id 17e9) when the dock is plugged in. I tried a bunch of things, including reverting from the 5.4 DisplayLink driver back to 5.3, but the only solution that worked was booting the previous kernel version (5.4.0-77), so it seems that some kernel change has caused the issue.

Just posting this in case it helps others or a developer is able to comment.

It's strange, because I'm currently using the 5.4 driver in Kubuntu 20.04 with kernel 5.4.0-80 successfully.
Perhaps a failed dkms installation?
You may try to boot with the 5.4.0-80 kernel, then run: sudo dkms autoinstall
to see whether it fixes the problem...