You will have to amend your 2017 tax return again to put it back the way it was originally, and report the Roth conversion on your 2019 tax return. You report transactions when they actually occur, not when you intended them to occur. You actually made a traditional IRA contribution in 2017 and you actually did a Roth conversion in 2019. That's the way you have to report it. The fact that you wish you had done it differently does not change what actually occurred.
