Incorrectly high amount computed for 2024 State and Local Taxes

Hello,

Turbotax calculated that I paid over $40,000 in state/local taxes in 2024, and advises I claim as an itemized deduction. But I don't understand how it arrived at that number of over $40,000.

I paid $28700 in 2024 toward California tax. This was a combination of estimated (Q3 $700, Q4 - paid in early 2025 - $13,000) and extension ($15,000) payments. My 2024 return (also prepared using Turbotax Desktop 2024) reflects this number on the Turbotax 2024 California Return Summary under "Total Payments/Credits" and 2024 Form 540, line 78. I claimed a California state tax refund of $2,812 (2024 Form 540, line 115), and my California tax owed in 2024 was $25,888 (as reported on the Turbotax 2024 California Return Summary).

I would expect the 2024 state tax that Turbotax 2025 thinks I owed to be $25,888. However, it somehow managed to compute it as slightly over $40,000, and reports this in Schedule A line 5a, claiming $40,000 as an itemized deduction. This seems incorrect, but I clearly must be misunderstanding something.

Here is how I entered the relevant data:

I visited the questionnaire under "Wages and Income"->"1099-MISC and other common income"->"State and Local Tax Refunds on Form 1099-G". The questionnaire asked me to report the refund received in 2025. I never got a 1099-G for my refund. Was I not supposed to enter this section?

Anyway, I entered my payments and withholdings there as $28,700, wrote in the amount of refund as $2,812. When done, it took me to a page that asked "Let's check for uncommon situations", "Select all tax payments you made during 2025 to these states or localities toward 2024 taxes".

I checked "2024 4th quarter estimated tax payment during 2025 to a state" and "Payment with a state extension filing", because, indeed, I made a 4th quarter estimated tax payment to California in January 2025, and an extension payment in April 2025. The next couple of pages asked me the amounts paid in estimated taxes in 2025 toward 2024, and the amount paid during the extension. The next page asked me what kind of deduction I took in 2024 (I took standard). Then it told me my refund isn't taxable and finished the questionnaire.

Under "Deductions and Credits"->"Estimates and Other Taxes Paid"->"Estimates", I entered the estimated taxes paid for 2025 for federal and state (together totaling $40,000), and checked the numbers that were already entered in the previous questionnaire for 2024 state estimated taxes in 2025 (they were correctly mentioned as $13,000, since this was the 2024 Q4 estimated tax I paid in Jan 2025).

Somehow, entering these things resulted in Turbotax calculating that I paid $40,257 toward state/local taxes, advising me to use itemized deductions, and filing $40,257 in Schedule A line 5a.

I'm probably misunderstanding something big here. I'd appreciate any help in the right direction.