@acha22
Are you confusing the 6475 letter for the third stimulus payment (you + 5 dependents = 6 on the return times 1400 = 8400) which means you got all of the third stimulus you are entitled to in advance. So did you not get that amount ... it went out starting in March thru the end of the year.
With the 6419 letter which reports the amount you got for the CTC advance ... they started going out monthly starting in July thru Dec ... these are totally separate things and are entered in totally separate places in the TT program.
https://www.irs.gov/credits-deductions/advance-child-tax-credit-payments-in-2021
