So, I can answer this question myself now that I have the product with me and have asked ATEN support. Finally, there are 2 suggested solutions which worked for me:
1. disable mouse emulation: for this I had to enter the following key combination:
1.1 Hold down [NumLock].
1.2 Press and release [-] (minus key).
1.3 Release [NumLock] again -> the ATEN KVM Switch beeps 2x
1.4 Press and release [m] (m button) -> The ATEN KVM Switch beeps 2x
2. via USB hub at the ATEN Keyboard USB port: for this I connected a powered USB hub to the ATEN Keyboard USB port. I then connected the wireless dongle of the mouse and the keyboard to the USB hub.
Here is the answer from our product experts:
Does this KVM keep the signal open for idle computers: In other words, if the computer's monitor and mouse :
1 (for example) are active, do computers 2, 3 and 4 think the monitor is still connected, or do they consider it disconnected?
Answer: Computers 2, 3 and 4 consider it disconnected.
2. So I have 4 monitors on my desk. If the KVM "disconnects" the split screen every time I switch desktops, it disrupts all the desktops when I switch.
Answer: According to our technician's tests, we could not see any icons moving on the Windows desktop.
Scope of delivery
1 x CS1914 4-Port USB 3.0 DisplayPort KVMP™ Switch
4 x LIN5-20K1-K14G DisplayPort cable
4 x LIN6-11C1-E12G USB 3.0 cable
4 x LIN5-0205-21CG Audio cable
1 x 0AD8-8005-40MG Power Supply Unit
1 x User manual
http://www.aten.com/de...