These USB switches seem to have problems, at least with Intel USB chipsets. I have two PCs where I had the same issue with two different USB switches - an old IOGear USB 2.0 switch and this new one. One PC is Alienware's top gaming laptop with an Intel USB controller. The second is an AMD based full tower gaming rig with an AMD chipset. The AMD system has no problems with this at all, while Intel only has problems. On a laptop, both the new and old Switch would randomly lose their keyboard several times an hour. Reconnect/switch back and the foam is back. However, with that USB switch, the mouse began to do the same. I actually solved the keyboard problem by disabling power management options on USB devices, but the mouse problem persisted. Looking at this online it seems to be a fairly common USB KVM Windows issue that has been around for years and never seems to have had a fix or comment from Microsoft or any other vendor. It's like an orphan's disease - there aren't enough people with a problem that the suppliers don't take care of.
Enhance Productivity with CKL HDMI KVM 2 Port 4K 30Hz Dual Monitor Extended Display (CKL-922HUA)
10 Review
CKL 4 Port KVM Switch Dual Monitor DisplayPort 4K 60Hz: Unprecedented Multi-Computer Control with Audio, USB 2.0 HUBS, and DP 1.2
11 Review
π TRENDnet TK-803R: 8-Port Rack Mount KVM Switch with VGA & USB Connection, USB/PS2 Support, Device Monitoring, Auto Scan - Control 8 Computers/Servers
10 Review
CKL Quad Monitor HDMI KVM Switch 4 Port 4K@30Hz with Cables - Extended and Mirrored Display Support for Windows, Linux, and Mac
11 Review