It does not effect 2019 at all other than being a 2019 non-deductible contribution (assuming that is is non-deductible) that will be reported on the 2019 8606 form as a contribution made between Jan 1, 2020 and Apr 15, 2020 on line 4 that will not affect your 2019 backdoor Roth since it will not apply until next year.
While you can contribute to a 2019 IRA up to the limit for 2019 before April 15, 2020 any distribution/conversion done in 2020 is a 2020 transaction reported next year on your 2020 tax return.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
