Are you using a desktop version of TurboTax? If so, enter Forms Mode and check your Schedule E and also check to see whether there is a Schedule A.
I cannot seem to reproduce the issue you are experiencing but then I do not know the exact steps you took to get that prompt in the review section. Regardless, do not enter your total interest twice. The program can do the split calculation for you but, frankly, you would probably fare better if you did the allocation yourself.
