First, I think the 930,000 / 1,100,000 seems correct under the 1,000,000 grandfather provision on loan originated before December 16, 2017.
I doubt TT calculations are sophisticated enough to find the nuance of the 930,000/1,110,000 as TT doesn't even handle refinancing correctly.
I would calculate 930/1100 percentage of interest paid manually and compare to what TT says. If different I would enter the 930/1100 time interest paid as override. If IRS questions you have calculations and intent to enter accurately.
I suspect TT will ask beginning balnce and then ending balance and will be aggressive and calculate interest deductible and 1,000,000/1,100,000 and calculate deduction from there. TT won't recognize 930,000 nuance.
