Does IRA distribution calculation (in 8606) prefer to take the taxable amounts first over non-taxable?

I had 0 in my IRA (12/31/23). Then I contributed $8000 nondeductible. Then I converted $8012 to roth-ira and by end of 2024 I had $20. So total interest $32, but I had already moved $12 of it out to roth. 8606 line 13 (nontaxable distribution) shows $7980 and line 14 (basis) $20. I'd expect 8k non taxable distribution frankly and maybe 0 basis? Is this a TT or an 8606 artifact? Thanks