Review on CKLau 4Kx2K Ultra HD 2-Port HDMI KVM Switch with USB 2.0 Hub and Audio Support - Control 2 Computers/DVR/NVR, Keyboard Mouse Switching for Linux, Windows, Mac, Unix by William Turner

We've been using two of them for our home office for about a month now. A 4 port and a 2 port. Both show the same problem. From time to time, and for no apparent reason, the USB ports on one or more (but not all) devices will simply turn off. Despite extensive testing, we could not find a common cause. Sometimes the error is temporary. After a few seconds, the USB ports will work again. Nothing works during this "shutdown"; as if all USB devices are disconnected. When this happens, it often happens multiple times in a row. When I'm writing a document or playing a game, I can expect my keyboard and mouse to drop out for 1-3 seconds every 60-90 seconds. If a button is pressed at the moment of the switch failure, the button will be repeated for 1-3 seconds. Sometimes the error is "permanent". In this case, the USB controller is disabled on the device. This causes me to turn off the device abruptly. Plugging another keyboard or mouse directly into the device's USB port does not work. This is a fatal error: the USB device should not be able to disable the host controller. This indicates a serious problem with the switch - possibly poor voltage regulation. At first I thought the "permanent" error mode was a problem with my devices. However, this has happened on my HP Elitebook, Dell Inspiron, Gigabyte Ryzen and ASRock i7 motherboards. The only devices connected are the keyboard and mouse. I've tried two different keyboards and two different mice, all with the same problem. I can alleviate the problem somewhat by connecting my USB devices to a USB 2.0 hub connected to the front port (as opposed to a dedicated keyboard/mouse). connections on the back). This reduces the number of cases from several times a day to several times a week. This isn't my gear; Something is wrong with this KVM switch. It is alarming that this is happening on both our 4 port and 2 port models. Of particular concern is the fact that the manufacturer has no support website or other means of contact. I am very concerned that continued use of these switches will permanently damage my hardware. I'm sending both back for a refund.