How old is/was your child? You need to double check what the IRS sent you for the first 2 Stimulus payments. Check your bank statements and even your IRS account. How much did you have on your original 1040 line 30 for the Recovery Rebate Credit? Line 30 is only if you didn't get the full amount or qualify for more. Not the amount you already got. The IRS shows you already got the first 2,900.
EIP1 The first Stimulus payment was 1,200 for each spouse and 500 for each dependent under 17. Came out in spring of 2020. So you should have received 1200+1200+500=2,900
EIP2 The second Stimulus was 600 per person and dependents under 17. The 2nd stimulus checks started going out at the very end of December 2020 and continued into January/Feb 2021. 600x3=1,800
The first 2 Stimulus payments went on your 2020 return even if you got the second one in Jan/Feb 2021.
