23-Jul-23 Update:
* I received a letter from the IRS. They now agree with the TurboTax calculations for Tax year 2021.
* They have refunded the additional tax and interest that I paid.
This is a good result for me and the rest of us taxpayers. Also, it is a good result for Intuit in that the IRS implicitly agrees that the mathematical computation in TurboTax is correct.
@Critter-3 @fanfare thank you for your comments.
@Anonymous good luck with your pursuit of this same issue with the IRS
