After you file

@UAU  the issue is normally related to not correctly entering what you received from the IRS for the stimulus into TT.

 

Did you use Letter 6475 to enter $2100 into Turbo Tax as the amount received? if you filed joint, there were TWO letters, one addressed to each spouse, so you were to enter $4200.  Is that what occured? 

 

Please look at your bank account statements from March - May, 2021? do you see a $4200 in deposits from the iRS? 

 

if yes, and there are just 3 people listed on your tax return, then Line 30 should be 0.  I suspect it is $2100.  That correct reduces your refund / increases what you owe by $2100.

 

if this is what occured, then the IRS is correct.