ok I see so you the contribution in 2013 was 2500, and in 2019 you had a gain to value of 5575 converted to Roth along with 6k in backdoor. this conversion contained a gain of 3075 which should have been taxable.
So you should have had an 8606 from 2013 onwards with a basis of $2500
then your 2019 8606 should show 6000 in line 1, 2500 on line 2 if that was your basis carried forward each year on those 8606s. Line 3 and Line 5 are 8500.
Line 8 would be 11575
LIne 10 is now 8500 / 11575=0.734
Line 11 = Line 13 is now 11575 * 0.734 =8500 - this is the amount of your conversion which is non-taxable
Line 14 is now zero and then your 5575 goes away
But line 16 should have been 3075, this is where you pay tax on the gain you had in the IRA.
I don't know what this means in terms of filing updated 8606s - or amendment and tax that was due for 2019 which is later than the 3 year amendment period; at the very least you probably need to send in updated 8606(s) for prior years which didn't affect the tax outcome and then when you file 2025 you won't have this 5575 any more. This article refers to amending prior year 8606s just needs that form sent to the IRS it doesn't require an amended return
https://ttlc.intuit.com/turbotax-support/en-us/help-article/retirement-benefits/enter-backdoor-roth-...
