Can't drag windows to second external monitor

[VinylChef]

Hi,

I have:

MacBook Pro M1 Max with DisplayLink software installed
i-tec CATRIPLEDOCKPRO docking hub
2 x LG 27G640A-B UltraGear™ G6 27-inch 300Hz QHD IPS Gaming Monitor

Both monitors are attached to the rear of the dock by HDMI.
The MacBook is connected to the powered USB-C port and is sending a signal to both monitors just fine.

Both monitors are showing wallpaper and the icons at the top of the screen.

Both displays are appearing in Systems Settings > Displays.
Both displays are appearing in the DisplayLink tab and they both show a red border when I hover my cursor over them.

However, when I run my cursor across the border of my MacBook it runs into one of the external monitors but not the other, so I can only effectively use one.

Interestingly, when I click on Finder, it opens a Finder window in the non-responsive monitor but I can't access it with my cursor.

Can you help me to solve this problem so I can use both monitors?

Many thanks,

David

[rboerner]

Given your description I suspect that you will just need to make a small change to how the displays are arranged in macOS.

Apple describes the 'Arrange' option here --> https://support.apple.com/guide/mac-help/displays-settings-on-mac-mh40768/mac

And a video that demonstrates the process in general is here --> https://youtu.be/PZxOHneRTMw?si=rHDiLDF2_T5yhLcU

[uabramov]

Thank you for the suggestion.

Unfortunately, this does not appear to be an arrangement issue within macOS. The displays are not being detected at all after updating to macOS 26.5.

Prior to the update, the FQQ quad monitor setup was functioning properly. Since updating, the unit no longer initializes or appears in Display Settings, even after reinstalling DisplayLink Manager, reconnecting cables, rebooting, and re-granting permissions.

This appears to be more of a DisplayLink/macOS compatibility issue rather than a display arrangement configuration problem.

If anyone has found a confirmed workaround specifically for FQQ or DisplayLink devices on macOS 26.5 with Apple Silicon (M3 Max), I would greatly appreciate the help.

[Szymon]

Please do not duplicate posts.

Szymon

[uabramov]

I wouldn't worry so much about duplicating right now.... I would rather worry about if you have a solution for this because is a really big problem if people who have MacBook.

[Szymon]

Please follow up in a dedicated thread, where I moved your original post:
https://www.displaylink.org/forum/showthread.php?t=69899

Regards,
Szymon

[VinylChef]

Hi Everyone,

Many thanks for replying. The problem seemed to disappear when I restarted my computer. I could have tried that before wasting people's time!

Kind regards,
David