MacBook Air M4: Two monitors not independent

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MacBook Air M4: Two monitors not independent

To connect 2 External Monitors to MacBook Air M4 :

I have a MacBook Air M4 2025. It's up to date and running on MacOs Tahoe Version 26.1

I have 2 external monitors one monitor of Philips and other is from HP... both are different models

If I plug them both into a USB C Dongle with 2 HDMI ports they both display the output of the macbook screen (when mirroring) or both can extend the macbook screen ... but they won't act independent of each other. They are detected as one display and just clone each other.

What adapter do I need to get both monitors working independently as 2 external displays?

Thanks.

Posted on Dec 14, 2025 6:50 AM

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Answer 1

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Servant of Cats

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Dec 14, 2025 7:38 AM in response to Ani077

You probably are using a plain USB-C hub or dock that uses DisplayPort MST to drive two video outputs. Macs do not support MST and the typical symptoms of trying to use it anyway are the ones you describe.

To drive two monitors from a single hub, dock, or dual-display adapter, it needs to be a Thunderbolt one. I would suggest looking at the offerings on the Other World Computing, SonnetTech, and CalDigit Web sites. Those three vendors are long-time suppliers of Thunderbolt gear for Macs.

Otherwise, you could plug one monitor into a plain USB-C dock, and the other directly into the MacBook Air’s other USB-C port.

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