@wyz - why are you confident that TT was buggy? is it possible you misunderstand how the Recovery Credit works and are going to do a lot of work for nothing?
if you post the following, I can quickly explain the math and might save you a lot of time and effort for naught:
1) how much was each of the 1st two stimulus payments?
2) what was your income on Line 11 (your AGI) - I suspect this will be the issue.
3) your filing status (married, single, etc)
4) number of children under the age of 17 as of 12/31/20 (i.e. born on or after 1/1/04)
