Turbo Tax is a self prepared return. It has no way of knowing or checking that you entered something wrong or in the wrong place or entered something twice Or left something out. It doesn't check against any outside sources. The IRS has copies of all the W2s and 1099s your employer and banks/brokers, etc. sent in to match against. Turbo Tax only checks the calculations of what you entered. It is your responsibility to check it over before you file. They only Guarantee that the calculations are right based on the entries you made.
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The Recovery Rebate Credit on Line 30 is only if you didn't get the full amount or qualify for more. The IRS records show they already sent it to you last year starting in March 2021. Double check your bank statements and Check your IRS account (both accounts if married)
Your Online Account | Internal Revenue Service
You tried to claim it again. If you didn't get the 3rd Stimulus payment you need to have the IRS put a trace on it.
