How much did the IRS actually send ? https://www.irs.gov/refunds
Did you indicate you did not get the $1400 third stimulus check in advance when asked ? Is there $1400 on line 30 of the form 1040? If the IRS says you got the advance you cannot also get the credit on the return. If you did not get the advance then you will need to have a trace put on the payment ...
If you don’t know how much stimulus you received, click Get My Payment
https://www.irs.gov/newsroom/questions-and-answers-about-the-third-economic-impact-payment-topic-j-p...
