Hi.
First of all. There is new macOS DisplayLink 5.2.1 beta 2 driver. Please make sure to have it installed:
https://www.displaylink.com/downloads/file?id=1433
Secondly, Can you please follow that instructions? Does any of them helps you?
https://support.displaylink.com/know...ing-permission
https://support.displaylink.com/know...lay-is-working
https://support.displaylink.com/know...-functionality
If you still have issues please gather diagnostic information and attach them in the post.
Please use our support tool:
https://www.displaylink.com/downloads/file?d=66
I would be grateful for output of terminal command:
sudo kextstat | grep DisplayLink