Is my KVM switch compatible with MacBook Air and PC?

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Level 1

4 points

Is my KVM switch compatible with MacBook Air and PC?

I want to use one monitor, keyboard, and mouse to switch between two computers. One computer is an M4 Macbook Air running Sequoia 15.4 and the other is a Dell Latitude 7450 running Windows 11 Enterprise. Both computers are connected via USB-C. If I leave the KVM switch on the Mac, it's no problem - the Mac wakes up ok after having been asleep for a while. If I leave it on the PC it's no problem either. If I switch from the Mac to the PC the PC acts fine as well, it wakes right up. The problem is when I'm on the PC for some time and switch back to the Mac. It basically doesn't wake up after multiple keyboard key presses or mouse clicks. I have to open the lid (I keep the lid closed for both laptops) to get the Macbook to wake up. Any ideas? In case it matters, the keyboard and mouse are both wired and are both non-Mac devices. The monitor is an hp HDMI device. I also keep the main power cable connected to the Macbook along with the USB-C; that doesn't help.

[Re-Titled by Moderator]

Original Title: Macbook Air with Anker 554

MacBook Air (M4, 2025)

Posted on Jul 19, 2025 04:06 PM

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Answer 1

Tesserax

Level 10

157,302 points

Jul 19, 2025 06:08 PM in response to moabster69

What you're describing is a known hiccup with how macOS handles clamshell mode and external USB input devices after sleep, particularly when those devices are passed through a USB-C dock or KVM switch like the Anker.

The root issue is that macOS (especially in clamshell mode) expects at least one of the following at the moment of sleep and wake:

External display must be active
USB or Bluetooth input device must be “seen” as active and consistent
Power adapter must be connected (which you already have covered)

When you switch the KVM away from the Mac, you're essentially removing both the USB input devices and the display, which macOS interprets as “no reason to wake up” later—especially since the lid is closed. It won't power up just from the USB reconnect because, at that point, macOS is in a deeper sleep state that expects a display to also be present to re-engage clamshell mode. That's why cracking the lid works—it forces the Mac to reinitialize everything.

So, what can be done to try to resolve this? Here are a few options you can consider trying:

Option 1: Use a Powered Dummy HDMI Plug

Plug a small HDMI dummy plug into the MacBook's KVM-attached display port (these simulate a display even when the KVM is switched away). This tricks the Mac into thinking a display is always attached. That way, when you switch the KVM back, the Mac still thinks it's in clamshell mode with a screen and will wake on USB input.

Option 2: Use Bluetooth Keyboard/Mouse

macOS handles Bluetooth wake events more reliably than hot-plugged USB through a dock.If your KVM supports Bl uetooth passthrough or if you use a shared Bluetooth device that can switch profiles, that can be a more consistent trigger to wake the Mac.

Option 3: Disable Deep Sleep

With macOS Sequoia, you can try adjusting the power settings:

sudo pmset -a standby 0
sudo pmset -a autopoweroff 0
sudo pmset -a displaysleep 10 disksleep 0 sleep 30

This keeps the system in a lighter sleep state, which might respond better to USB activity.

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