If you got letter 6475 then the IRS is saying you did get the 3rd Stimulus check EIP3. You can't find a bank deposit for that amount? If you are married they send letter 6475 to each spouse for half. You don't need to post all the IRS info. We know it. They sent the 3rd Stimulus based on your 2020 return to get the checks out fast. But it is really based on 2021, so the Recovery Rebate Credit could be more or less.
If you got letter 6475 but did not get the 3rd payment that came out starting in March 2021 last year then you need to put a trace for the missing third Stimulus payment
https://www.irs.gov/newsroom/questions-and-answers-about-the-third-economic-impact-payment-topic-j-p...
