It would be normal to see that both Federal and state returns will be filed when you're trying to file only the state. The state return has to piggyback on the Federal return to be electronically filed. The Federal will just be seen as a duplicate filing since it has already been accepted by the IRS when you electronically filed it earlier.
Take a look at the following TurboTax help article for further guidance:
How do I e-file my state after I already filed my federal?