The reasons given by IRS are:
Details:
We changed the amount claimed as Recovery Rebate Credit on your tax return. The error was in one or more of the following:
The Social Security number of one or more individuals claimed as a qualifying dependent was missing or incomplete.
The last name of one or more individuals claimed as a qualifying dependent does not match our records.
One or more individuals claimed as a qualifying dependent exceeds the age limit.
Your adjusted gross income exceeds $75,000 ($150,000 if married filing jointly, $112,500 if head of household).
The amount was computed incorrectly.
