MS Loan Amortization Schedule doesn't calculate the same monthly payment by bank did

I am trying to add my RV loan to the MS template called Loan amortization schedule excel spreadsheet. My loan is 15 years (180 payments), loan amount is $42,127.77 at an APR of 9.74%. The scheduled payment calculated in the loan amortization spreadsheet is $446.03, but my bank has us paying $453.27. I zero'd optional extra payments for now but might add them later. How do I fix this discrepancy in the calculation and why is it happening? What should I be looking for?