The type of investment is irrelevant. The amount you are distributing for 2019 is $6,000. The amount of your 2020 and 2021 contributions that you are recharacterizing is also each $6,000 regardless of the investment performance. The investment performance attributable to your 2020 and 2021 contributions only determines the adjusted amount that gets transferred to the traditional IRA.
There are no Forms 1099-R related to any of this to be entered on your 2020 tax return. Your 2020 tax return should only include an explanation statement describing the recharacterized 2020 contribution.
