I think you are getting confused over the difference between the Statements Provided by Your Lender averaging method you are using and the First and Last Balance averaging method Turbo Tax uses. Both methods are described on page 12 of Pub 936.
For the Statements Provided by Your Lender, you use the ending balance on your statements. The reference point is the ending balance for the month. For the month the loan was paid off, this amount should be $0.
For the First and Last Balance method, you use the balance on the last day in the year the loan was secured by the home. The reference point is midnight 31 DEC 2024 if you did not payoff the loan in 2024 and midnight the day before the payoff date if you did pay off the loan.
