Got my KVM DP 1.4 - USB switching works, I have no image

Hi everyone,
I’ve just received my new 1.4 Display Port KVM Switch - Dual Monitor - Four Computer form L1T and I have some issues with it. I got good cables (Club3D displayport 1.4 1m and 2m), but I cannot get it to work. Usb switching works fine, but I’m not getting any image and monitor is not detected by my PC. Currently I have only one monitor with Display Port (Asus TUF Gaming VG27AQ) and I’ve just realised that it’s only supporting display port 1.2, not 1.4 - can that be the issue there? It works if I connect it directly to the PC with those Display port 1.4 cables, so I don’t think it’s the cable issue.
What should I do now? How can I check if KVM is not faulty? Am I doing something wrong?

What GPU are you using? Can you take a pic of how you have it cabled?