Prevailing Wage Fringes Not Calculating Correctly

SUGGESTED

We have the base rate and fringe set up per job for prevailing wage and the fringes for employee pay marked as required for certified pay as well as the hourly calculations entered in the payroll set up. However, the certified payroll shows that some employees are being overpaid on the fringe rate while others underpaid. Has anyone else had this happen? Sage set up our PR Cash Fringe formula and we aren't able to decipher if this is wrong in some way 

Any help is appreciated.