Retirement tax questions

I am in the same situation - first time doing backdoor Roth (with post tax money).  Now 2019, I have 1099R now.  Filing 2018 return to cover two Roth conversion transactions happening in 2018.  Following the steps, but the 2017 $5500 became taxable in 2018's 1040 line 4. This is not correct, right?  Did I do something wrong in Turbo Tax?  Help!  Thanks!