The code-8 Form 1099-R is a distribution to you of excess contributions to the original 401(k) and was not eligible for rollover to the IRA, perhaps due to the plan failing nondiscrimination testing. If the amount on the code-8 Form 1099-R was rolled over to the IRA, it represents a regular contribution to the traditional IRA, perhaps an excess contribution, not a rollover contribution; this amount would need to be entered under Deductions & Credits as a regular traditional IRA contribution. If this results in an excess traditional IRA contribution, you have until the due date of your 2020 tax return to obtain an explicit return of contribution to avoid recurring 6% excess contribution penalties on the excess.
The amount shown on the code-8 Form 1099-R is taxable to you but is not subject to any early-distribution penalty. It should appear on line 1 of your Form 1040 as wages rather than on lines 5a and 5b. However, any investment gains in the IRA required to be distributed with a return of contribution would be subject to tax and, if you are under age 59½, early-distribution penalty on your 2020 tax return.
