Local Tax Element Not calculating correctly on Separate Check

Summary:

We have a local tax that is not calculating correctly when we process regular and separate check for an employee. Instead of calculating on the Gross Earnings of separate run the system takes into account Regular run earnings too. Any idea how to fix this issue? We have customized the FF of this element.

  
                                                                   Regular Run              Separate Run
Gross Earnings                2500             100

Tax Rate                      0.006            0.006

Current system Calculation    15              15.6 (2500 + 100)

Expected Calculation          15               0.6


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