After you file

@gaby1254 - here is how it MAY have occured as there are others with similar situations on this site.

 

in 2020, you and your spouse had a dependent, so that generated a $4200 stimulus payment ($1400 for each family member) 

 

in 2021, the dependent remained on your tax return 

 

you AND YOUR SPOUSE received letters from the IRS stating that the stimulus payment was $2100.  

 

This was confusing because what should have occured is that you entered $4200 (the sum of BOTH letters) into TT, but you may not have realized they needed to be added together or may not have realized your spouse also received a letter. 

 

So you entered $2100 into Turbo Tax.  TT realized your were entited to $4200 and you entered you only received $2100, so TT put the different or $2100 on Line 30. 

 

When the IRS reviewed the return, they knew they sent you $4200 and they could see you were entitled to $4200, so they removed the amount on Line 30

 

make sense?