KVM mouse and keyboard issue  

Have a four device HDMI KVM switch. Handles HDMI 2.0 at 60 hz video and audio perfectly with all my devices which are
3 PCs and 1 set top Blu-ray player.

Main screen is a 27 inch LS 4k monitor. am using a logitech KB and Mouse
PC on port 1 is Windows 11 vers 21H2
PC on port 2 is Windows 10 Pro 64 bit version 22H2 build 19045.3693
PC on port 3 is Windows 10 Pro 64 bit
Item on port 4 is a set top LG Blu-Ray Player controlled with separate remote.

ALL ports work perfectly and pass full 4k at 30 hz and audio to the LG Ultra 4K monitor.
The Windows 11 PC on port 1 also works perfectly with the Logitec Mouse and keyboard.

But both the windows 10 PCs have horrible stuttering and intermittant control with the mouse and keyboard. So bad I can not use those PCs ... Video and audio ARE perfect on ALL ports but KB and Mouse stutter on the win 10 PCs make them almost impossible to use.

Tried swapping and testing all the cables and ports ... SEEMS to be a windows 10 issue of some sort. Have done driver deleting and reinstalling etc. Note if I remove those win 10 PCs from the KVM switch and plug in their wireless dongles directly into those PCs without the KVM switch in play, they work normal.

And they USED to work okay with my older 3 Port KVM BUT the old KVM and old monitor were NOT HDMI or 4K. I suppose I "could" finally upgrade those 2 win 10 PCs to 11 and "maybe" then everything might work ?

Just wondering if anyone had any experience with these HDMI KVM switches made for 4K video HDMI ?

Not exactly. Maybe the chipset drivers (affecting the USB drivers) need updating. Use Speccy or Aida64 to check what exactly is your chipset (mine for example is Intel H61) and then see if you can find newer drivers to install. In an old workstation motherboard I had, the USB ports could barely detect a mouse and keyboard with the Intel USB drivers. They could not detect properly a USB flash drive or other USB device. I tried 2-3 chipset drivers and didn't make any difference. I decided to try the Microsoft generic drivers. I expanded the USB devices tree and I right-clicked on each "Intel USB..." device, selected Update Drivers and then the second option (manually check). Then the second option again (manually select). I was presented with a small list containing a couple of Intel USB devices and a generic USB device equivalent. I selected the generic one. After doing that for all devices and replaced all Intel drivers with generic I restarted the computer. The USB ports then worked perfectly detecting all USB devices. Of course this is as a last resort solution. Try some chipset drivers first. Also avoid using USB 3.0 (blue plastic) or higher ports with the KVM. Try the USB 2.0 ports (black plastic) first.

Many thanks for the info. As far as the KVM usb ports go .. this fancy KVM has true 3.1 USB ports only and the very minimual and vague one paragraph with multiple pictures manual does mention something about it working best with good USB 3.0 or better cables AND they supply with the unit four USB 3 cables to use. One of the things I wanted was additional true USB 3 cabablity to be able to use the 3 pc's own usb 3 input with that kvm. Then I could plug anything into one of the empty USB ports on KVM (like a USB Key or portable drive, CD or what ever) and be able to use that plugged in device with any of the three PCs.

So wouldn't downgrading the KVM usb cable to USB 2 kinda be a step backwards?

I will check the chipset drivers as suggested .. that sounds possible and could be why the Win 11 PC mouse and KB does work perfectly and only the Win 10 PCs have issues with the mouse and KB. I'm still waiting to hear from logitech support about this.

The mouse and keyboard are both logitech, a K270 KB and a G305 Mouse.

Logitech does have software for the mouse and keyboard but it is to program the programmable keys. It doesn't need to make the device work.

Thanks everyone. It WAS an issue with the USB ports. Both the win 10 PCs had multiple "banks" of on board USB 3 ports. Thanks to the replies here I was able to find the problem. In the end I found that one bank of USB port drivers just would not work with the USB cable that was being fed by the KVM switch. Nothing helped. So I studied my mother boards owner's diagrams and found which usb ports were running on which banks of ports. And I moved the KVM usb 3 cable from the problem bank to a different one. And now both the KB and Mouse work perfectly. Once I had that 2nd PC working perfectly I went to the 3rd PC and did NOT even try to adjust anything but simply moved the KVM's USB Cable to a different bank of USB ports. And that solved the problem.

So I'd suggest the first thing someone should do if having a similar problem would be to refer to their owner's Mobo manual and find which USB ports are linked to which bank and then try moving your KVM usb cable to a usb port on another bank.

It's curious to me why the two PCs in question had this same problem and they both had totally different Mobo's from different manufacturers. Both had keyboard and mouse problems with a specific USB bank of ports but worked ok on a differnt bank. Both banks in my situation were USB 3 and were part of the back plane mobo external mobo connections. All I had to do was to move the USB cable from one port to a different one. Hope this helps: (one picture worth 1K words?) <grin>