Payroll Tax Calculation on Bonus

My employer kindly gave some employees a Christmas bonus without telling me or running it through QBO payroll.  I now need to create a bonus cheque in Quickbooks online payroll to track the bonus correctly.  I understand how to create a bonus cheque in QBO, but no matter what I do, the tax calculations are way off.  I compare all payroll cheques created in QBO payroll to the CRA payroll calculator as a double check.  Normally the two systems are identical or if there's a discrepancy I can find the source of the problem.  However, when it comes to recreating the bonus cheques in QBO, the source deductions calculations in QBO are very different from the CRA payroll calculator. 

For instance, I need to create a net pay cheque of $750.00 so I selected the QBO net pay bonus calculation option.  QBO indicates the following calculations for this employee that has NOT met CPP or EI maximums for 2020:

Gross Bonus Payment should be: $1,130.57

Income Tax:  $303.36

Employee EI:  $17.86

Employee CPP: $59.35

Employer EI:  $25.00

Employer CPP: $59.35

Net Pay:  $750.00

If I enter a gross payment of $1,130.57 in the CRA payroll calculator to double check the QBO calculations I show the following:

Income Tax:  $100.84

Employee CPP:  $52.29

Employee EI:  $17.86

Employer CPP: $52.29

Employer EI:  $25.00

Net Pay:  $959.58

That's a discrepancy of over $200.00 and I can't figure out why.  I thought the discrepancy may stem from the 2021 TD-1 tax update so I manually changed the amounts back to the 2020 amounts and it is still calculating incorrectly.   Is there something I'm missing that would cause such a discrepancy?