Retirement tax questions

On the TurboTax form 1099-R I filled in my gross distribution in box 1 and entered zero as the taxable amount in box 2a. I then followed the interview and checked all the correct buttons for a full rollover, but when I run the check entries at the end of TurboTax, it points out that the taxable amount cannot be zero. But when I change the zero amount in box 2a to match the gross distribution in box 1, it has me paying taxes on the full amount of the RMD even though I rolled it over. Is this a bug?