For over a year I have been using a Macbook Pro (M1 2020) with two identical Dell P2419H monitors and a J5Create JCD543 docking station. Yesterday the HDMI port in the J5Create docking station failed and their support folks couldn't fix it. So I replaced it with a Belkin USB-C 11-in-1 multiport dock.

My problem is that now the two Dell monitors work, but they're mirroring each other (displaying identical screens). One has a HDMI cable and one has a DP cable, and they're both plugged into the Belkin dock.

When I go to System Preferences and Displays to fix the mirroring, it doesn't "know" I have two displays. Instead, it only shows one of the Dell monitors.

Pressing the Alt button in Displays to go from Night Shift to Detect Monitors doesn't work. Nothing happens. Neither does the usual round of unplugging/plugging in the monitors and restarting.

I also checked Privacy and Security to make sure that Allow Accessories to Connect is set on Always.

I have the Belkin docking station plugged into one of the Macbook's USB C ports and the power cord plugged into the other.

I suspect I may need to downgrade from Ventura 13.2.1 as others have reported similar problems, but I haven't found anyone with my EXACT problem.

(If you're wondering why I chose the monitor/Macbook combination, I didn't; they were company issued.)

  • This behavior began when the J5Create docking station failed, and it was replaced by a different docking station from Belkin. Nothing else changed. This strongly suggests that the behavior change was caused by the two docking stations being not precisely the same. Can you locate (perhaps even borrow) a J5Create dock and try substitution-back-to-original? We don't know where you are, but both Amazon and eBay show many listings for new and used JCD543s. Mar 18, 2023 at 19:01

1 Answer 1


Downgrading from Ventura 13.2.1 will not fix your problem.

You specify the model for the J5Create as JCD543, but omit the model for the Belkin USB-C 11-in-1 multiport dock. Quick search and I get INC004btSGY. I hope I am lucky and this is your model.

You Mac natively only supports one external monitor which can be mirrored or extended. The Belkin INC004btSGY can allow more monitors, but only if the monitors mirror each other. Belkin various websites do explain this as a limitation of macOS.

On the other hand, the J5Create JCD543 gets around this limitation by having you install software which allows macOS to think there more monitors than can be supported natively. One method, of detecting such software is to be employed, is when a message such as the following appears.

enter image description here

The above image was taken from a PDF instruction file included in the software I downloaded for the J5Create JCD543.

Note: The use of software which allows for one or more external monitors can also slow down your Mac.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .