TurboTax is aware of the 1098's not adding together when there are two 1098's from a refinance. 

Here is the current work-around:

1. Gather all of your 1098 forms related to your refinance (the form from your original lender and the form from your new lender)
2. Grab a calculator and add together the box 1 amount from each form. Enter the total in TurboTax as Box 1 Mortgage interest.
3. Add the Box 5 amount from each form and enter the total as Box 5 Mortgage insurance premiums. (If you weren’t required to pay mortgage interest, these boxes will be blank on your forms and you won’t enter anything.)
4. Add the property tax paid from each form and enter it in the Property (real estate) taxes box.

Next, finish adding info for boxes 2, 3, 7, and 11 using Form 1098 for the original loan.

Amend is scheduled to be available in TurboTax in late March.  When amend is available, you can make the changes needed and then e-file the amend for federal and state.  

Multiple 1098's 

If Turbotax is aware of this issue and they need time to fix this, why are they not warning the users when they detect more than two 1098 forms being entered.
I ran into this. I have three 1098s due to two refinances in 2020 and TurboTax is calculating incorrect mortgage interest. I just spent 4 hrs trying to re-enter the forms and trying different things.
I am super annoyed with the time I wasted and I am thinking of using a different website to file my taxes next year.