Grand total not summing up correctly on pre-agg calculated field

We have a pre-agg calculation fixed at a lower grain and in the visual we roll it up to higher grain. The values obtained at lower grain are accurate but while rolling up, it re-calculates at higer grain. we want the result at higher grain to be summation of column values instead of recalulation at higher grain. The pre-agg field is summed up running along with conditional statement

What is your current calculated field?