How can I enter two 1098's for a mortgage transferred during the year without the mortgage balance being double counted (thus limiting the mortgage interest deduction)?

My mortgage was transferred to a new lender during 2020 (not refinanced or paid off). I entered the values for both 1098's in TurboTax. If I include non-zero values for "Outstanding principle balance" for either lender, TurboTax seems to count the two lenders as seperate mortgages that together exceed the $750000 limit, thus greatly reducing my mortgage interest deduction. This seems to have been a problem in prior years as well. How can I prevent the double counting without setting "Outstanding principle balance" to zero?