Uninstalled Duet drivers, and...
 

So, this is interesting. I remembered that I'd installed Duet Display so that I could use my iPad as a second monitor last fall. For laughs, I uninstalled the Duet Display drivers *and* the DisplayLink drivers, disconnected the DisplayLink adaptor, restarted, then re-installed DisplayLink 5.1.1 drivers. Restarted again, plugged in the DisplayLink monitor, and...

Lo and behold, the DisplayLink monitor works correctly now! Not sure if this is a "just me" fix (the sequence of steps/troubleshooting only applies to my situation) or if this is something that might apply to others. Also, I haven't extensively tested it (i.e., haven't unplugged the monitor and plugged it back in, rebooted the laptop, etc.) but it appears there may be hope.

I'm using a Diamond Multimedia USB3 to DisplayPort adaptor with a DisplayLink DL-5500 chipset in it.

Same issue here. I chatted with ASUS staffs three times, but it has not still resolved... My external monitor seems like receiving a signal, but it's still a black screen. Does anyone have a solution for this issue? This is really inconvenience... :mad:

2018 Macbook Pro
macOS Mojave v. 10.14.5
DisplayLink USB Graphics Software for macOS 5.1.1

DVI Port is the problem.
 

My Displaylink has 1 DVI, and 1 HDMI. If I only used the HDMI everything is fine, but once I connect the DVI, things get flaky. The DVI extends on top of one of the HDMI screens.

For now is working my extended screen
 

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.:D

Same issue on my Macbook Pro with 10.14.6 Mojave using DisplayLink Driver 5.2.15

See my post here: https://www.displaylink.org/forum/sh...28&postcount=3

Same issue on my Macbook Pro 13"

Macbook Pro: 13", 2017
macOS version: 10.14.6
DisplayLink driver: 5.2 (15)

The Desktop get mirror on the 2nd external screen connected via DP and daisy chain from 1st Dell monitor to 2nd Dell monitor but not extended.

What you describe is a DisplayPort MST setup, also referred to as daisy chaining. macOS does not support DisplayPort MST setups with multiple displays. That is why both displays in the chain are mirrored. To put that another way, the behavior you are seeing is the result of an operating system limitation.

Oh Ok thanks for letting me know. Guess that will not be fixed from Apple.

Cheers