Macbook Pro M4 recognizing dual external displays as one monitor

Are these Thunderbolt docks?

Macs do not support DisplayPort MST daisy-chaining or its equivalent. If you use

• A plain USB-C dock that provides two or more display outputs, using this method; or
• A Thunderbolt dock that provides three or more display outputs, using this method

you are virtually guaranteed to run into problems like the one you describe.

It is very common for the extra displays to get a "mirrored" signal rather than to get no signal at all. But as far as the Mac is concerned, there are no extra displays. It is seeing a connection to one display, and the dock is (essentially) replicating that signal to the other display behind the Mac's back.

First, see if you can get both displays going on separate cables as separate displays.

Then if you want more than one display on a cable, the computer port, the cable, and the first device (Dock or Thunderbolt Display) must be bona-fide Thunderbolt.

USB-C has only half the bandwidth, and the Mac does not connect two displays on a USB-C cable or USB-C Dock.

“Macbook Pro M4 recognizing dual external displays as one monitor“

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Extending External Displays on a Mac:

See what Google has highlighted here: Extend or mirror your Mac desktop across multiple displays - Apple Support

“The issue in the settings is that only one external display is recognized. The system treats both monitors as a single display instead of recognizing them as two separate screens.”

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Make these Extended (not Mirrored) Displays:

So, making these two monitors to be expended displays is not an option for you? It seems all you are able to do here is mirror the displays. Is that correct?

Amount of Displays on a Mac:

On some Mac’s, you can only attach and use one external display, and not two. So, what’s the model of your Mac? Google it and find out what AI answer is provided for the amount of displays you can use with it.

are the two the exact same model?

what make & Model displays?

TheLittles wrote:

Amount of Displays on a Mac:

On some Mac’s, you can only attach and use one external display, and not two. So, what’s the model of your Mac?

The OP told us the he or she has a MacBook Pro M4. The tag line indicates that is a 14" one.

MacBook Pro (14-inch, M4, 2024) - Tech Specs - Apple Support

MacBook Pro (14-inch, M4 Pro or M4 Max, 2024) - Tech Specs - Apple Support

So the remaining question would be whether the OP's MBP has a plain M4 chip, a M4 Pro chip, or a M4 Max one. Even a MBP with a plain M4 chip can drive two external displays, with a refresh rate of 60 Hz, with the lid open (a first for any Mac notebook with a plain M-series chip).

Google it and find out what AI answer is provided for the amount of displays you can use with it.

I would suggest relying on Apple's Technical Specifications and other Support documentation, rather than on the "AI answer" you might get from a Google search.

ASUS PG27AQDM appears to be 2560 by 1440 with HDR (10 bit color) and up to 240Hz refresh rate

2x HDMI

1x DisplayPort 1.4

it also has USB 3.2 on a type-A connector, but that is not an acceptable display input

LG 27GL83A appears to be a 2560 by 1440 display with nominal 10 bits color (may use FRC) up to 144 Hz refresh

1x displayPort

1x HDMI

so how are you attempting to connect these?

does each work with its own cable?

do both work at the same time with their own cables?