if i understand correcty what you did your form 8606 for 2021 should show a basis of $6000 on line 2 {the 2021 contribution made in 2022) then line 1 should show $6000 for the non deductible contribution you made in 2022 for 2022. line 8 should show $12K for the conversions. line 11 should be the same (assuming line 6 is zero). line 16 and 17 should both be $12K assuming line 6 is zero.
