After you file

Thank you for any help you can provide.
The code is R....For a little more background In 2017 I made contributions to a ROTH IRA.  In Jan 2018 I recharacterized those to a traditional IRA when I realized my income was too high to invest in a ROTH.  Because I had not yet filed my 2017 taxes, this recharacterization was annotated on my tax return.  Now I receive 1099-R and Turbo Tax says I ‘MAY’ need to amend my 2017 return.  So two questions, do I need to amend my 2017 return?  And why doesn’t turbo tax know if I need to since I filed with turbo tax last year??