Am I doing something wrong or is there a problem with the program or my data set?

I have a payroll which includes a reimbursment income code.  This is a true, non-taxable reimbursement - employees hand in actual receipts for expenditures made on behalf of the employer and get reimbursed, with the amounts being added to their paycheques purely for convenience.  It is not actually part of wages for T4, WCB, CPP, or EI purposes.  The income code was incorrectly set as 'income' when it was set up last year, and the problem was discovered and corrected when we were doing last year's T4's.  Changing the income code to 'reimbursement' correctly removed the reimbursements from T4 box 14.  I don't know if it also fixed CPP'able and EI'able earnings, as everyone who got the reimbursement was at maximum even before the reimbursement.

Until we did the T4 fix, the income code was set as 'income' type and all of the 'calculate this' columns were unticked in setup.  After the T4 fix, the income code is set as 'reimbursement' and all of the 'calculate this' columns are still unticked in setup.

We had already done a couple of payrolls in 2019 before we discovered the T4 fix.  On those payrolls, the WCB, EI, and CPP were correctly calculated without including the reimbursement.

For payrolls calculated after the T4 fix, with the code correctly set as 'reimbursement', Sage is incorrectly calculating CPP, EI, and WCB on the reimbursement, and is including reimbursements paid in 2019 after the T4 fix (but not reimbursments paid in 2019 before the T4 fix) in Box 14 earnings, CPP'able earnings, and EI'able earnings.

Any suggestions for how to fix this?