Yes many have, maybe millions. It's a common problem. The IRS is reviewing all returns that have an amount on 1040 line 30 for the Recovery rebate credit.
Did you receive the full amount for both the first 2 Stimulus payments? Better check your 1040 line 30 and see if an amount is listed. That's been a problem. A common adjustment is if you claimed the Recovery rebate credit on 1040 line 30 when you already got the Stimulus payments or got the second one after you filed. Or you might have answered the Stimulus questions wrong and tried to claim it again or some more on line 30. So the IRS took it off because you already got it. They know they sent it to you.
If you claimed a missing stimulus payment on your return but the IRS took it off you have to ask the IRS. They think they already sent it to you. Maybe it went to an account you don't remember. Or you got a check or a card. It was probably easy to miss the debit card in the mail and think it was junk mail. They have to put a trace on it.
How to put a trace on a missing 1st or 2nd Stimulus payment. IRS for Payment Issued but Lost, Stolen, Destroyed or Not Received
See question F3 here, you can expand it to see how to put a trace on it.
https://www.irs.gov/newsroom/2020-recovery-rebate-credit-topic-f-finding-the-first-and-second-econom...
