There is a serious problem with the dynamic brake behaviour on the AC4400 on PS4. The braking force decreases as speed increases and increases as speed decreases. This is contrary to what is supposed to happen. This leads to it being impossible to hold a steady braking force at anything other than a very low speed with the dynamic brakes, because as the speed increases slightly, the braking force decreases and cause a further increase in speed. If the speed decreases slightly the braking force increases and the speed continues to fall. On the heavy grain train for instance there is the strange situation where you can hold the train at lower speed than 8mph with a large brake force being applied in notch 3 but on the same grade be unable to hold it at 20mph on notch 8, where the braking force quickly diminishes as the train gets faster beyond around 12mph. With dynamic brake systems the maximum braking force is at around 24mph and reduces as the train gets slower. On the AC4400 on PS4 the opposite is true. It is very broken. The dynamic brakes on the SD40, for example work as expected, with the amps, and therefore the braking force, rising as speed increases. This needs to be investigated by DTG (and fixed) but I would also like to know if there is the same problem on PC and xbox and for other players to report if they are getting the same incorrect behaviour from the AC4400.