Advance payments in 2021 on child tax credit

The advance child tax credits are confusing me. We decided to take the advance credits for the 6 months starting July 2021 and were expecting to get the other half in 2022 of the $1500 based on the letter that went out from the Biden administration on 6/25/21. We qualify for this based on AGI so I'm wondering why I'm having to pay for Federal this year as I was expecting to get the extra $1500 when filing taxes and I'm not? We have our Federal tax withholdings set so each year we get less of a return or break just about even and have it spready out through the year, so maybe that's it? Since we meet the requirements to get the full $3000, half in 2021 and the other in 2022 should we be expecting the other $1500?