TAS is a public relations arm of IRS that is even less effective now that its staffing has been seriously reduced.  However, they are good at writing memos.  This sounds like the taxpayer received a "math error notice," and didn't request abatement within 60 days.  TAS has a memo for that. It doesn't say, "bring us the problem."

https://www.taxpayeradvocate.irs.gov/wp-content/uploads/2023/01/ARC22_PurpleBook_03_ImproveAssmtColl...