for most 1099s including 1099-INT the only things that must be entered are the payer's name and the amounts on the various lines on the form. The additional payer, recipient's address and zip are not and have never been required information for (e) filing a return. It is not sent when you e-file. if you file my mail you'll notice that info is nowhere to be found in the tax forms. Entering the TIN was probably to import data when importing from a Turbotax partner. Then Turbotax probably used that info transferred from the prior year's return to match to the current year's form so you would not have duplicate forms in your return.
FEIN is the same as its TIN