Quickbooks stopped sending the tax payments with the cents in 2021. Since you could not edit the amount in the software this caused an issue but they have fixed this and I have not had the issue since 2020. Yes, they did sent them with cents and yes it created a rounding error, hence why the IRS sent the letter. You could make your own payment in even dollars if you don't want to use the software but it has been fixed for a while now.