The weird result I am seeing is not caused by the monitor. Also, it is not caused by the different refresh rate and stabilised plate current. I am getting the same things over and over again, and the test show that there is a significant deviation to what I was expecting. I can’t think of any other thing I might have missed, and the results are pretty consistent. I currently have 10 matlab figures open and can see the same pattern over and over again. Okay, the coefficients are different, but the other monitor is brighter, smaller and behaves differently.
To do an other verification, I will make a circuit, and will check it with LEDs as well. This tendency should vanish.