I am not a tax expert but 2400 sounds like the distribution under the Trump administration which was considered 2020 paid out in January 2021 that was 600 per dependent. The other is referring to the 3rd stimulus check that for a family of 4 was 5600. That was received somewhere between late feb to may. As I first stated the letter the IRS did not include my dependents in how much they paid they only included Taxpayer and spouse in the letter. The children dependents were not included in the letter. The only way to confirm what was paid is by looking at the bank account.
