TT calculates penalty based on the information it's been given, the calculation on Form 2210 is straightforward especially if not adopting Annualized Income method. But IRS calculates the penalty independently, based on what they know for safe harbor amount based on 2023/2024 AGI/Tax, ES payment dates etc. Suggest looking further into why IRS vs. TT was different to avoid same in 2025. Also, if you usually get a penalty every year you may need to adjust withholding or pay some estimated tax.
