Constant Reactive Power, Variable Real Power Output

Hi - I am currently doing a simulation in PowerWorld where there is simply a generator transmission line and load. The Q of the load is being kept constant and the P is being increased from 0 to Q. From this, the load bus voltage is being plotted against the P drawn from the generator. The curve should first be downward (lower bus voltage when increased power is being drawn) and then at some point (~P = 0.5Q) flatten out and then continue upwards (higher bus voltage when increased power is being drawn). I an unable to get these results from PowerWorld. However, I also do not understand why this would happen. Wouldn't higher P lead to higher S, which in turn leads to higher current, more losses and lower load bus voltage?

Thanks!