2 Port DisplayPort KVM Switch - 4K 60Hz - Compact Dual Port UHD DP 1.2 USB Desktop KVM Switch with 4ft Cables & Audio - Bus Powered & Remote Switching - MacBook ThinkPad

Monitors may begin flickering when they receive a signal of insufficient quality. There are a few potential fixes available that will help to improve the signal quality in order to eliminate flickering:

• Replace Video Cables with high-quality Video Cables (e.g. upgrade DisplayPort 1.2 Cables to DisplayPort 1.4 Cables).
• Use shorter Video Cables to reduce signal attenuation.
• When possible, remove Video Adapters to use native Video Connection Types (e.g. go from VGA to VGA, or DisplayPort to DisplayPort)
• For DisplayPort Monitors, try changing the DisplayPort Version on the Monitor. For information on how to change your Monitor Settings refer to the Manual from the Monitor Manufacturer.
• Update the Drivers for the Computer’s GPU to the latest available from the Monitor Manufacturer.

1. Ensure the video & USB cables are connected between each computer and the KVM switch
2. Safely power off all computers.  Unplug everything from the KVM switch and connect one computer at a time, swapping the inputs previously used (e.g., the computer connected to PC2 now connects to PC1). Power on each computer and confirm functionality before connecting the next one to the KVM switch. 
   • If using a KVM switch that supports multiple displays, ensure all video connections from the computer are from either the video card or motherboard, both cannot be used simultaneously on most systems.