RSU Payout Not Included in W-2

I have a weird situation that I haven't seen listed yet.  Over the last several years, I've been granted RSUs.  In one instance, the RSUs were vested and paid out and reported as income on my W-2. In another instance, an RSU was paid out when the account was closed, and not included in my W-2 but added to 1099-B without a cost basis.  If I'm reading this right, the cost basis should be the same as the payout/proceeds, even though it's not listed on the 1099-B.  Is that accurate?  Thank you!