Unrealistic gravity physics?

I have a rocket that applies a force of 1000kg upwards, the weight of the rocket is 2000kg. The thrust to weight ratio is 0.5 meaning there is not enough thrust to push the rocket upwards however the rocket still accelerates upward for some reason. Is there a better way to simulate gravity as this is a simply calculation but it does not work in unreal engine, and this is extremely important to my game?

Did you accidenttaly tick Accel Change? With a standard gravity of 9.81 (at least here, on Mother Earth), this will create lift off: