The missing amount is $600 ? The amount of the second stimulus check ? Look on your return ... form 1040 line 30 ... is the missing amount there ? If so you said you did not get the second stimulus payment and the IRS says you did ... this was not a TT error. So look at your account on the IRS site ... do they indicate the payment was sent ? And did you get it but forgot ? Or got it after you filed ?