Hi, A few days ago I bought a Samsung monitor S27D850T 2560x1440p that I connected to my macbook pro 13 inch (2017) with a displayport cable to type-c. However, I have seen that there is a lag of the mouse and the keyboard, that is to say that the movements of the mouse do not follow exactly my movements in milliseconds. Sometimes I play fps games but unfortunately it has become very difficult to play with. Between the monitor and the macbook, there is no hub, it is directly a cable that connects them. By cons, I was able to test with a USB hub by a HDMI cable and it was even worse. I could already configure the reaction time of my monitor on "accelerated". I did a test to see the reaction time between the screen of my macbook pro and that of the monitor on a website and I could see that there is still about 20ms difference between two which shows that the monitor is late. However, In addition, the screen of the macbook also have like 10ms input lag (I think) and it shows that the real time of reaction between my macbook and the monitor is even greater. So my question: Is it normal that there is such a huge reaction time? Can this come from my cable that I bought on aliexpress ?