At all junctions of beam and column , the sum of all the end  moments in a plane say XY or ZY must be zero, as per the established law of equilibrium. In the staad output as also the design end moments for the beams and columns are observed to be different for the same load case. Why it is so? Some where I remember to have studied that staad does only one round of moment distribution. Can that be the reason? If it is so then can we manually balance the moment and design the beam and column as per the balanced moment . Generally the column end moment works out to be more than beam end moment. What is the reason for the unbalanced moment.. One round of  moment distribution does not appeal to me. The moment at the end of column is not the same as that at the start of the column of upper storey. Can this be manually adjusted?

Please clarify.