After you file

If you already received all of the EIP payments then you answered incorrectly on your tax return if you tried to get those payments again as a recovery rebate credit.   If you received those payments you should have entered the amounts from letter 6475 that was sent to EACH spouse so that you would not have had an amount on line 30.   You cannot get the recovery rebate credit if you already received the EIP payment.  If you  had an amount on line 30 you were trying to get the $1400 per person twice.   You do not get it twice.

LOTS of people have made mistakes this year with the recovery rebate credit by "forgetting" that they received the $1400 per person stimulus checks last year.  They answered no to the questions for the  recovery recovery rebate credit and put the $1400 per person on line 30 of their returns.  But you cannot get it twice, so the IRS removes it when it is there by mistake.  The IRS sent letter 6475 showing that you received the 3rd stimulus check. 

It is very important that if you filed a joint return—-the IRS sent letter 6475 to EACH spouse.  You had to enter the total amount received.   Many people misunderstood and entered only the amount from one of the letters.

Try checking your online account with the IRS (and if you filed a joint return—check for BOTH of you)

https://www.irs.gov/payments/your-online-account

Does the IRS show that you received a $1400 per person stimulus or EIP check in 2021?   Did you receive it?   When you were asked on your tax return did you say no?   Was there $1400 per person on line 30 of your tax return?

If the IRS says you got $1400  per person last year but you did not receive it you can have it traced.

LOST THIRD STIMULUS CHECK

https://www.irs.gov/newsroom/questions-and-answers-about-the-third-round-economic-impact-payment-top...

If you need to trace a payment that the IRS says has been issued to you, mail or fax a completed IRS Form 3911, Taxpayer Statement Regarding Refund