Update: the IRS confirmed, sort of, that it was an error on their end and will be modifying the payment to reflect payment of my tax bill rather than estimated taxes.
Thank you for all those who posted helpful comments to get me going in the right direction.
To the others? If you want to help you should really take the time to read what the question actually is and determine if you are answering it. It is your time that you are wasting otherwise.
Which brings me to TurboTax. It is pretty sad that they have completely crowdsourced their support. It seems reasonable to charge for additional tax preparation support. But it seem utterly insane that they provide no pathway to address potential technical questions. Forcing everyone into a chatbot, and not even a good one at that, shows utter disregard for customers who have many potential alternatives.
