2020 Recovery Rebate Credit Error

TT said I was eligible for a first payment of $1847 and second payment of $747.  I recieved less than that for each payment (and verified in my IRS account that I entered my two payments of 1217 and 550 correctly).  I then was given a credit of $827 by TTax which I later had to Repay.  Where did the $1847 and $747 TTax said I was eligible come from based on my AGI? I entered the info correctly, why did this calculation occur?  Now that I'm filing for 2021 TTax is importing the incorrect info on that and on total taxes owed/paid.  How do I fix it?