Mismatch Between FV Function and the Bankrate Simple Savings Calculator

I'm trying to replicate the functionality of the Bankrate Simple Savings Calculator in Google Sheets. I've assumed that I need to use the FV function, but I can't get the numbers to match exactly. Here's what my Google Sheets spreadsheet looks like:

[A]                 [B]
 Initial Deposit         \$100,000
 Monthly Contributions   \$500
 Over a period of        10        (years)
 APY                     2.4%

FV          \$194,830.57      ...using =FV(B4/12,B3*12,-B2,-B1,0)
Bankrate    \$194,410.60      ...using https://www.bankrate.com/calculators/savings/simple-savings-calculator.aspx

FV - Bankrate = \$419.97 difference          ...why?

Using the FV function with a rate of 2.4/12, a number of periods of 10*12, a payment amount of -\$500, and a present value of -\$100,000 yields \$194,830.57, but the same numbers in the Bankrate calculator come out to \$194,410.60. This is a difference of \$419.97.

I suspect that 2.4% APY in the Bankrate calculator is not the same as 2.4% in the FV function, but can someone explain why and how to fix the FV version so that it matches the Bankrate calculator? Thanks!