All Mac devices seem to prevent scroll lock hotkey switching

Level1 Store KVM Helpdesk
1

KVM Model:

1.4 Display Port KVM Switch - Dual Monitor - Two Computer

USB Interface (5-gigabit or 10-gigbit):

5-gigabit

Problem:

Scroll lock hotkeys work on Windows but not when I switch to any Mac

Other Notes:

I’ve got a 2-computer/2 display DP 1.4 KVM that has, until recently, been working flawlessly. I use it to switch between my gaming PC and my work macbook/personal mac studio. I have the first input directly connected to my PC, while the mac input is connected to a CalDigit TS4, and I just manually connect/disconnect the thunderbolt cable when switching between my personal and work mac.

Things were working fine for months, but suddenly for some reason the hotkeys have stopped working when I switch to any mac input, regardless of system. I have an Apollo 80 keyboard, which is a tenkeyless mechanical keyboard running QMK firmware. I have my scroll lock key bound to the second layer on my keyboard so that the toggle is easier to reach.

I don’t think it’s an issue with my hardware, as I can disconnect the thunderbolt cable from one of the macs and then switch back just fine. It feels like it has something to do with a recent MacOS update changing how it handles keyboard input or something. All my devices are running MacOS Sonoma.

Any info or troubleshooting steps would be appreciated!

2

Have you tried power cycling the KVM? By that I mean unplug everything and leave it for a couple of minutes, then plug it back in?

3

I haven’t done that yet, but I’ll give it a go.

Also, my original theory of it being a macOS issue is no longer valid. I tried hooking up a Windows laptop and encountered the same issue. It seems that it only occurs on the second input when any device is plugged in via the CalDigit TS4. I’ll power cycle and see if anything changes.

4

Okay, so I’ve done some more fiddling with the KVM and it seems like the actual problem is input 2 whenever ANY usb device is plugged in; I was only testing macs on the second input. I tried swapping inputs from my PC and the CalDigit dock that I had over to the new one but no dice. I can switch from 1 → 2 but I can’t go back.

Of note, it appears that the green light only shows on input 1 but not input 2. Not quite sure what that means in this context as all of my USB devices work normally on the input.

5

This would imply the KVM does not detect that the USB connection is there at all. The green light is powered by the USB ports even if the KVM is unplugged to show there is a connection. I have not seen this other than a cable not being plugged in correctly…

Can you get a quick video of its behavior?