IRS says 1040 stimulus miscalculation. How to fix?

Like many others, I got a letter than the IRS found a miscalculation. "We changed the amount claimed as Recovery Rebate Credit on your tax return". I went from a federal refund of $1355 to owing $1145.
In Turbo Tax, it says I received an estimated first round/second round of $3195/$2195 when the actual numbers were 3400/2400, so off by $410.

In TurboTax it just says these (wrong) numbers are what we're eligible for and "The good news is, if you got more money than what we've calculated, you don't have to pay it back, There are no penalties or consequences, you just get to keep it."

 

Well it sounds like there were some other consequences!

If it matters, the IRS's calculations for AGI and Taxable income match my return. My AGI in Turbotax is just over $150k for 2020.