It is working for now for me,
I have Mojave with Samsungs Monitors.
Go to System Preference => Security and Privacy
Under the tab Privacy find Accessibility
You will see the display link app, Remove the Display link app and reboot the computer. You can edit unlocking it with your login credentials.
That app was to use it for the Airplay, which now is no longer needed with the DisplayLink 5.1.1 version.
Hope this help.
