Review on 🔁 CKL DisplayPort KVM Switch 2 Port with Cables 4K@60Hz 4:4:4 321DP" - Optimized DisplayPort KVM Switch 2 Port with Cables | 4K@60Hz & 4:4:4 | CKL 321DP by Dave Goodman

I upgraded my monitors to 4K and bought this switch to use. It has been found that only flashing or black screens appear when the resolution is set to 60Hz. I've tried multiple cables in different configurations with no success. I ran cables straight from the PC to the monitors and 60Hz works fine. After contacting Revain, their response was to simply issue a return and refund instead of replacing the Switch, as they believe all of these devices could have the same issue. I told them they need to update the specs page because it is false advertising. Their response was that they were "working" on it. Be aware that this switch (at least the one they sent me) cannot handle 4K at 60Hz. If you're happy with 30Hz, then you're probably fine. But for what I paid for the switch, graphics card, and monitors, I expect it to perform as advertised.