After you file

This is not a TT issue ... if the user enters the wrong amount of the advance stimulus payments in the interview screen then the IRS will delay the return in processing and recomputed the return using the correct amount ... this is clearly a user entry error.  See the screen shots below ... the program explained it all to you ...

The IRS letter to come will explain what they changed and why but until then look at the form 1040 line 30 ... if you got all the stimulus money up front then line 30 should be blank or a zero... you are not allowed to "double dip".