Question : SQL Report Sort

I am using a matrix Tablix and for some reason or other I cant figure out how to sort a column I have included som pics below to show what I have done..

I need to sort on the Short/Surplus Column...

Answer : SQL Report Sort

Try sorting by the entire expression in the column including the Sum, [Sum(UnitDiffMonthlyTotal)], and see if that is all it takes.  If that is not the fix I will try to replicate it, but that will take time.