Thank you so much @GSD77 At around 3am last night I FINALLY figured out the mixed mortgage and Table I and at the end also came up with the portion of mixed Interest that I could deduct, just as you said.
For Table I, (mixed mortgage) use line 2 for line 12 (the amount of qualified interest allowed/refinanced by Loan 2 (mixed loan) - from Loan 1 Home Acquisition Debt. (line 2)
Divide Line 12 by Avg monthly balance of entire mixed loan = a fraction, in my case, 0.850
ex. 0.85 x Interest paid on mixed mortgage (Loan 2)*
= DEDUCTIBLE portion of the mixed mtg Interest
Now, I will see whether I can input this into TT and get the correct amount. Sigh...
*in my case as we refinanced in 2020
Note: 100% of my Loan 1 interest is deductible
