Mac recognizing dual external displays as one monitor

Hi


I am trying to connect my two JVC external monitors to my M1 Macbook Pro 13. I am not using any cheap connector but using a HP G5 Docking station to connect both monitors. The problem is both monitors are on. and showing the same display as each other. however, in the system display settings, I only see one external monitor connected. the second monitor isn't even showing up there. even though both monitors show the same display together.


I have installed Display Link Manager. and have checked all cables. tried with DisplayPort 1.4. but no success.


Any ideas on how to fix this?

Posted on Oct 10, 2025 2:41 PM

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Posted on Oct 10, 2025 10:20 PM

There are a couple of problems here.


One is that the 13" M1 MacBook Pro only supports a single external monitor.

MacBook Pro (13-inch, M1, 2020) - Technical Specifications - Apple Support


The other is that even if you had a Mac that supported two or more external monitors, you could not hook up both of them using that dock.


The HP USB-C Dock G5 looks like a plain USB-C dock with three places to plug in displays: two DisplayPort ports and a HDMI 2.0 port. I see no indication that this dock uses DisplayLink or other second-class workarounds – and thus my guess would be that it drives three displays using DisplayPort MST.


Macs don't support MST and only support driving one display from a plain USB-C dock, or two from a Thunderbolt dock. A typical symptom of using a Mac that supports multiple monitors with a dock that uses MST – and plugging two displays into said dock – is that the Mac only sees one display, while both displays seem to always run in "mirror" mode (since the dock is feeding copies of a single video signal to both of them). (In your case, there would only be one video signal even if you were using a Thunderbolt dock.)


I'm not surprised that installing DisplayLink Manager had no effect. That software only works in connection with an external "stunt box" that contains a corresponding "magic decoder ring" chip set. Neither a "stunt box" alone, nor the software alone, will get you any video outputs.

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Question marked as Top-ranking reply

Oct 10, 2025 10:20 PM in response to Airmanspore

There are a couple of problems here.


One is that the 13" M1 MacBook Pro only supports a single external monitor.

MacBook Pro (13-inch, M1, 2020) - Technical Specifications - Apple Support


The other is that even if you had a Mac that supported two or more external monitors, you could not hook up both of them using that dock.


The HP USB-C Dock G5 looks like a plain USB-C dock with three places to plug in displays: two DisplayPort ports and a HDMI 2.0 port. I see no indication that this dock uses DisplayLink or other second-class workarounds – and thus my guess would be that it drives three displays using DisplayPort MST.


Macs don't support MST and only support driving one display from a plain USB-C dock, or two from a Thunderbolt dock. A typical symptom of using a Mac that supports multiple monitors with a dock that uses MST – and plugging two displays into said dock – is that the Mac only sees one display, while both displays seem to always run in "mirror" mode (since the dock is feeding copies of a single video signal to both of them). (In your case, there would only be one video signal even if you were using a Thunderbolt dock.)


I'm not surprised that installing DisplayLink Manager had no effect. That software only works in connection with an external "stunt box" that contains a corresponding "magic decoder ring" chip set. Neither a "stunt box" alone, nor the software alone, will get you any video outputs.

Mac recognizing dual external displays as one monitor

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