Ubuntu 22.04 with DL 5.6.1 is laggy if no WGA screen plugged

[jules]

Hello the Community,

I recently updated my computer (not a laptop) to Ubuntu 22.04 (installation from scratch, new hdd)
I installed the DIsplay Link Driver version 5.6.1
I have 3 Screens connected to the Display Link.

The 3 screens are laggy if the Display Link Device is used alone (no other screen plugged to the computer)

The 3 screens work fine only if I connect a WGA screen at computer startup. Then I can unplug this VGA screen, the other screens continue to work

Previously, I was using the same computer with an Ubuntu version 20.04 and Display Link version 5.5 without any issue.

Any way to solve this? thanks


echo "$XDG_SESSION_TYPE"
returns wayland

uname -a
Linux jules-server 5.15.0-52-generic #58-Ubuntu SMP Thu Oct 13 08:03:55 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux

[jules]

Hello,

I found the "$XDG_SESSION_TYPE" is defined to the value "X11" when no screen is plug to the computer video card.
The $XDG_SESSION_TYPE" value is back to "wayland" when the gdm.service is restarted manually, and everything is working fine again.
systemctl restart gdm.service

It seems there is a service startup issue between the dispalylink-driver.service service and the gdm.service despite the dispalylink-driver.service is defined to run before the gdm.service

systemctl list-dependencies gdm.service --before

gdm.service
● ├─displaylink-driver.service
● ├─graphical.target
○ │ ├─systemd-update-utmp-runlevel.service
○ │ └─shutdown.target
○ └─shutdown.target

May the USB / displaylink the not fully initialized yet when the gdm starts ?