Contributed to Nondeductible Traditional IRA but mistakenly reported as Roth IRA contribution

2019/01 - 1st time made a $5500 contribution to T-IRA as nondeductible for tax year 2018

2019/02 - did backdoor Roth IRA conversion of $5500.

2019/03 - made a $6000 contribution to T-IRA as nondeductible for tax year 2019

2019/03 - did backdoor Roth IRA conversion of $6000.

 

Just realize now that in my 2018 return, I mistakenly reported $5500 Roth IRA direct contribution instead of nondeductible T-IRA contribution hence Turbo tax didn't trigger form 8606. 

 

My 2018 AGI was $115,000 which was under the $120,000 income limitation threshold for that year. Theoretically my 2018 tax return reported as direct Roth IRA contribution is legitimate, but it was not the way I did the contribution in my Fidelity IRA accounts. It is now beyond 3 years timeline of amendment. Anyway to fix this error ? Any consequences for not fixing it ?

 

Thanks