Clamshell Mode on MacBook Air M4 Not Working

Question

Clamshell Mode on MacBook Air M4 Not Working

I recently upgraded to Tahoe (26.0.1) and clamshell mode is no longer working. I have to have my laptop lid open to be able to use my external monitor (it will only extend or mirror). The monitor light shows that it's connected to my MBA, but the display doesn't show up unless I open the lid. If I close the lid, the MBA does not sleep, and the mouse and keyboard still work and will select or take actions but the display is not showing anything. Prior to upgrading, this functionality worked just fine. I'm using a Wavlink thunderbolt hub and using the same thunderbolt port to charge and power my MBA. Like I said, this setup was working prior to the upgrade.

I have a MacBook Air (13-inch, M4, 2025) running Tahoe (26.0.1). With Ventura, I did not have this issue.

I also had to change my display rate from 75 Hz to 60 Hz just to get the display to work at all. However, the external display will not work while the MBA has the lid closed (clamshell mode). Apple has removed the settings to enable/disable clamshell mode, and for some reason it isn't working when powering via the thunderbolt port or the magsafe port. I can have the laptop powered by the magsafe and have the thunderbolt port plugged in and the display will not work on my MBA unless the lid is open. I've tried changing the display rate to 50 Hz with no luck.

What am I missing?

MacBook Air 13″

Posted on Oct 3, 2025 2:01 AM

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Answer 1

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juggernaut115 Author

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4 points

Oct 3, 2025 2:07 PM in response to juggernaut115

As a workaround, I can plug the monitor into a thunderbolt port on my Wavlink WL-UTD45 using the HDMI-to-Thunderbolt adapter and that also allows my MBA to work in clamshell mode with my Wavlink. This appears to be something with the HDMI ports on my Wavlink. I'll provide an updated post once I hear back from Wavlink.

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Answer 2

Oct 3, 2025 2:08 PM in response to neuroanatomist

Using the adapter directly to the MBA works. In addition, as a workaround, I can plug the monitor into a thunderbolt port on my Wavlink WL-UTD45 using the HDMI-to-Thunderbolt adapter and that also allows my MBA to work in clamshell mode with my Wavlink. This appears to be something with the HDMI ports on my Wavlink. I'll provide an updated post once I hear back from Wavlink.

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Answer 3

Oct 3, 2025 4:14 AM in response to juggernaut115

Does clamshell mode work properly if you don’t use the dock (i.e., connect the display and power directly to the Mac)?

At least some Wavlink docks use DisplayLink, and those drivers often lag in support for macOS updates.

FWIW, clamshell mode is working fine for me with an M4 MBP running 26.0.1 with display/power via a single cable from a Stone Pro TB3 dock.

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Answer 4

Oct 3, 2025 7:39 AM in response to juggernaut115

That is a bit odd, yes. FYI, HDMI and DisplayLink are different concepts. HDMI and DisplayPort are two different types of cables/ports. DisplayLink is a software 'hack' that enables pseudo-support for more displays than a computer is natively capable of supporting (the displays are not hardware-accelerated, and tend to lag).

Worth noting that macOS has become progressively less tolerant of video data packet loss due to sub-par cables. There have been several reports of setups that worked in Sequoia not working in Tahoe, with nothing changed but macOS.

Best recommendation for that at this point is to try a new cable. Be sure to use high quality cables – HDMI should be labeled Ultra or Premium. That random cable you found in a drawer might or might not work.

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Answer 5

Oct 3, 2025 2:03 PM in response to juggernaut115

Using a HDMI-to-Thunderbolt adapter allows me to use my MBA in clamshell mode. I will work with Wavlink support and find out what options they may have on an updated driver/firmware.

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Answer 6

Oct 3, 2025 7:11 AM in response to neuroanatomist

I'll test it tonight, but I'm using HDMI to the Wavlink. I'm not using DisplayLink. Wavlink doesn't have any updated firmware or drivers I can use. However, it does work when the lid is open. It's possible, I may need to wait for Wavlink to release a newer driver version for Tahoe. This is a simple Thunderbolt 4 hub and has worked great with Sequoia. I got Ventura wrong above, and it won't let me edit it.

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Answer 7

Oct 3, 2025 2:30 PM in response to neuroanatomist

I'm able to use the exact HDMI cable, just with an HDMI-to-Thunderbolt adapter. I'm not leveraging the DisplayLink software. I used it when I had a Dell docking station I used to use for my work laptop, and switched it out to the Wavlink. But I'm good with leveraging the adapter w/ my Wavlink since that's working.

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Answer 8

Oct 3, 2025 10:29 AM in response to juggernaut115

I have a thunderbolt 4 to HDMI adapter arriving today and will test a direct connection. If that works, I'll reach out to Wavlink support and see what they have to say.

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Answer 9

Oct 3, 2025 2:06 PM in response to juggernaut115

Thanks for the update, hope they can sort it out. Isolating the problem was the first step.

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