FWIW, I had the same issue. TurboTax's calculation was off by $135 (55%). The good news for me is that it overestimated the penalty, so I'll be getting a small refund. However, I'm concerned it will complicate matters when I file an amended return (due to receipt of a late corrected 1099).
The information I provided for my 2024 estimated tax payments was accurate. TT seems to have miscalculated one of the 4 underpayment amounts and 2 of the 4 days late. I'm not sure how that happens unless there's a bug in the software. And, if this is not a bug but just something that can happen due to the IRS using different information, shouldn't TT warn users about it before they file? I don't recall seeing any message about it. In fact, it wasn't immediately obvious to me that I had to pay a penalty at all.
