Yes, this is correct and you are fine with filing as is. The IRS merely used 2019 information for 2020 tax year to make an estimation as to what was "fair" by person. Given that we are a cash-basis type tax return, the money received in 2020, although based on 2019 information, is being updated to what you should have received (or needed in 2020) versus what you did receive and what they thought you needed due to extreme difference between 2019 and 2020. It is right and correct.
