Amplitude modulation greater than the combined field


I have been comparing the amplitude modulation of two LF simulations and their combined field. For some reason, the value of the combined field is not always higher than that of the amplitude modulation which does not make sense. Does anyone know why I might be getting this?


Update: I manually summed the fields and got an answer that makes more sense (sum is always greater than amplitude modulation). I am not sure where it is going wrong when I am using the field combiner.