When you have two 1098 forms with selling a house with one lender and buying a house with a new lender in 2020 then yes, you enter both 1098s one at a time. After going through the steps with the first one, you can add a lender when you get to the Mortgage deduction summary screen. You would NOT enter them together as one unless it is a refinance.
Here is a TurboTax FAQ about deducting Mortgage interest.
