I have done this every year before and it usually lowers my tax bill immediately upon entering it. I've tried the registration line and the property tax line and neither are lowering my tax bill.
It sounds like TurboTax has determined that you'd be better off taking the Standard Deduction instead of Itemizing Deductions (which would include the auto registration).
Perhaps you're not done entering all your deductions that would go on the Itemized Deduction Schedule. Do you still have mortgage interest, property taxes, charitable donations, etc to enter?
Sadly I do not recall the outcome of this situation. I did not take the standard deduction, nor was it the best choice for me - so I don't know why it was doing that. Thanks for your answer. It seems like even if I had not entered all my deductions, it should have moved the needle on the refund meter. But perhaps not, since I cannot recall I apologize for not being able to help. Again, thank you for the response. Whatever the problem was, I worked it out at the time. LOL.