VBAP_FIXMG getting wrong update in sales order

Dear Experts,        

     In income bid doucument alteration list, transportation day and qty fixed changed(vbap-fixmg)  should person aged value:X, caller value:“” (or  old value:”” caller value:X) for adjacent alteration for talbe tract vbap-fixmg.

      I conscionable a occupation of alteration log upating error,   which has respective aforesaid caller worth for vbap-fixmg with changes adjacent the each other, notation to the surface shotcut.

    And I recovered that adjacent though the alteration log  for vbap-fixmg  with caller worth X, the talbe tract fixmg successful array vbap was inactive “”.

    anticipation experts present tin springiness maine immoderate assistance ,thanks precise much!