My name is not on mortgage but on title. I have paid off the mortgage and will claim the deduction. Lender just sent a 1099-int with my ex name. Do i report it?

It depends what the 1099-INT is for. It's unusual for the lender to pay the borrower interest. If this is related to your mortgage, such as a refund of interest you paid, then yes, you should report it, but probably as a reduction in the amount of interest that you paid.

If it's just interest paid on a different account, then no.