"Fidelity "informed" me that I can make additional $5,500 contribution that will be counted as 2018 contribution. So, I went ahead and did it..."
If you took an IRA deduction of $5,500 on your 2018 tax return,
which is basically what Fidelity was encouraging you to do,
you can't submit a 2018 8606 that says it was non-deductible.
So, which is it ? How did you file on the 2018 return?
