Displaylink is not supported (M1 and Dell display)

[TakoTaro]

I am using a Displaylink compatible Plugable, USBC-6950U. I have the following problem.
OS: mac 12.0.1
DisplayLink Manager 1.6.0

Q. On my Mac M1 (Mac book air), I cannot display the screen using Display Link. How can I get the screen to appear?
No screen appears, but sometimes a white screen appears only for a short time, about 0.2 seconds, and the display side is receiving the HDMI signal.

<What I have tried >
- Check whether the manufacturing ID of the Plugable conversion cable is a number such as 8080 when checked on the Mac side -> 0x6... No problem.

- The Mac side recognizes the Dell display (S2721Q) connected by the Plugable, and I can check the resolution and other status of the Dell display from the Preferences.

- When I used Windows instead of Mac, the connection using Displaylink with Plugable was possible and the display appeared.

- When I used Displaylink with another Dell display as the connection destination on mac m1, the connection was possible => Therefore, I think there may be a problem with Dell display S2721Q and am contacting Dell support. I have not received a reply yet.

Please tell me if anyone has the same situation in the same environment in this form.
Thank you.