I'm in the same boat! Just received a CP11 (on 9/21/2021) with the very same claims made in the original post. Equally, everything stated earlier is also true about my case. My case is even a bit simpler. MFJ, both children are >17, received only one EIP, all personal data is correct and verified. Everything is rock solid. I cannot find any errors. It looks as if the only variable in the computation is the amount previously received for the EIPs. Mine also match the IRS records (website) and it matches my bank account as well. And no, like the Does, my wife and I did not receive individual payments. Sadly, I have not been able to reach the IRS at their stated phone # to discuss. Equally sad is that the only recourse if you disagree is to call the IRS (800) 829-8374 - no answers, just recordings that all agents are busy and that I need to call back on the next business day. So, my question is: Does Intuit have an appropriate or canned response that can be used as a template for responding in writing to the IRS? I am a self-preparer using TT. My dog was not involved, he wanted to be, but I made him "stay".