Question KVM -USB headaches

[ouch]

Hi all,
I've got a cheapish HDMI KVM switch that is being used to switch between a (homebuilt) PC and a work-issued laptop. Said KVM has 2 USB ports, which is sub optimal as I'd like to switch a USB headset and Webcam as well. The problem is that the KVM doesn't seem to play nice with any USB hubs downstream of it.

I've tried 2 USB hubs so far, a cheap, compact one and then a more expensive one from a known manufacturer. Both seem to exhibit similar issues of the webcam and headset devices not being recognized when plugged in, mouse and keyboard work most the time. I'm now wondering if there's some sort of DDM going on or something that's messing things up and it's not actually an issue with the hub, but with the KVM itself.

Webcam a logitech C270
Headset is a plantronics C3220
Keyboard is Logitech ultra X
Mouse is a Dell WM514

Does anyone know if this might be the case? Am I asking for trouble plugging a USB hub in downstream of a KVM regardless? Would a KVM like this be better if I used the non K/M usb ports for other peripherals/downstream hub?

 

[Deleted member 14196]

I wouldn’t plug a USB hub in downstream while using a KVM because that’s not going to work

 

[ouch]

yep,

Did some research based on @Mandark advice.

so it turns out that KVMs don't treat all USB ports equally, those marked for keyboard and mouse are conditioned in such a way as to make the computer think there' something attached, even when it isnt - this interefere with anything else that might be plugged in, such as a webcam or headset.
There's a small number of KVMs on the market which have additional ports for purely switching USB and not keyboard and mouse, such as this one which is now working (mostly)