Maxsurt does not correct calculate beam max on waterline for catamaran

Hi every one,
Does any meet the problem as picture shown in below during calculate the hydrostatics for catamaran by using Maxsurf Stability or Maxsurf Modeler? From the image, it looks like at admidship draft t=1.623 the value of beam max on WL was incorrect lead to the Cb value was incorrect at the same draft?
Thanks in advance