USB HID ports not working on L1KVM

I just received and set up my L1 KVM today! I have the Dual Monitor, Two Computer, USB 10 Gbps version, and unfortunately I am having an issue. The USB 3 ports work, but the USB 2 ports do not.

I currently have only one computer to test with: a 2019 MacBook Pro. The connection path is Thunderbolt 3 → Plugable TBT3-UDZ dock → KVM → monitors. The USB cable I’m using is the “Monoprice Essentials USB Type-C to USB Type-A 3.1 Gen 2 Cable, 10Gbps, 3A, 30AWG, Black, 1m (3.3ft)” (product number 24287, I’d link but am not allowed), but because the USB 3 ports work, I don’t think that that is the issue.

I have 3 USB devices I’ve tried to connect: a Melody96 keyboard running QMK, a Motu M2 audio interface, and a Logitech webcam. All of these are USB 2.0 devices. Whenever they are connected to either of the two USB 3 ports on the KVM, they are detected by the computer and work properly. When they are connected to any of the HID ports on the KVM, they receive power but are not detected by the computer.

Has this issue been seen before with the 10 Gbps KVMs? Is there a compatibility option I could enable somewhere? Is it likely an issue with my computer, dock, or USB devices?


The hid ports are meant for hid devices. You can use a powered usb3 hub for more regular USB ports.

The usb3 ports reset when switching but the USB hid ports don’t

If you have a cheap $5 keyboard try that and see if the hid ports work with that. If it does then the other USB devices are doing something weird

I use qmk on my keyboard which works fine on the hid ports. But only if nkey rollover is disabled.

Thank you, that was indeed the problem.

I swapped the audio interface and webcam to a hub connected to one of the USB3 ports on the KVM and left the keyboard connected to a HID port. Everything now works as expected, including the hotkeys.

It is interesting that “foreign” devices on the HID ports broke all USB communication, but now that I’ve thought about what the KVM must be doing in order to listen for the hotkeys, it makes sense that it would be sensitive to exactly what communication was happening.

I also got to connect the second computer today, and everything works great! I’m especially impressed that when switching away from the Mac laptop, it recognizes that the monitors have been disconnected and moves windows back to the internal display. That doesn’t usually happen when simply changing the source on a monitor that has multiple inputs.

Thanks for your help!