8a is a correct presentation. If you REALLY need to have it in 8b then click the Carryovers/Misc Info in the upper right  and scroll down the last entry and enter a 1 = yes.

8a Totals for all long-term transactions reported on Form
1099-B for which basis was reported to the IRS and for
which you have no adjustments (see instructions).
However, if you choose to report all these transactions
on Form 8949, leave this line blank and go to line 8b .