Unable to use 3 screens with an hdmi adapter

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Unable to use 3 screens with an hdmi adapter

I am unable to use 3 screens with my adapter. I have 3 screens or monitors. My MAC / laptop screen, and 2 separate DELL screens. It appears my 2 DELL screens are mirroring each other and not displaying or working as separate screens.

Image below shows my adapter, and the hdmi cables which go to each individual DELL screen.

I also can't seem to find the right configuration setting on my settings . As seen beneath, it also only shows 1 DELL monitor.

The adapter is from Amazon and can be found here: https://www.amazon.com/Adapter-KOZYC-Multiport-Splitter-Extended/dp/B0CGDCGN6Z?th=1

[Edited by Moderator]

MacBook Air 13″, macOS 14.6

Posted on Sep 27, 2025 2:54 PM

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Answer 1

Top-ranking reply

Servant of Cats

Level 7

34,481 points

Sep 27, 2025 3:34 PM in response to Michaelamay0

To connect two displays to a single dock, hub, or dual-display adapter in a hardware-supported way, all of the following conditions must hold.

The Mac needs to support two or more external displays
The Mac needs to have a Thunderbolt port
The dock, hub, or dual-display adapter needs to be a Thunderbolt device, not a plain USB-C one

That's not the case here.

The 13" M1 MacBook Pro supports one external display. Not two or three.

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

Macs do not support DisplayPort MST daisy-chaining or its equivalent. Even if you had a Mac that supported multiple external monitors, you couldn't connect two to that adapter, and run them in extended desktop mode. Amazon's description of that adapter makes a nod to that when it says "(MST is not Supported on MacOS)."

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Answer 2

Michaelamay0 Author

Level 1

4 points

Sep 27, 2025 3:02 PM in response to Michaelamay0

I think I found the solution, its related to my mac m1 chip, and i need a special adapter and download a driver.

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