I am still running into this problem and am still waiting on a TT fix. However, I think I can explain why some people see this as fixed and others see it as not fixed. There are 2 pages to the Form 8615 Schedule D Worksheet - the first for the child and the second for the family. It appears the problem is fixed on the Child's page/page 1 (Child's Line 15 Schedule D Tax Calculation), but it is NOT fixed on the Family page/page 2 (Family's Aggregate Line 9 Schedule D Tax Calculation).
On the latest TT (desktop), I tested this theory it works as I describe. If you get Line 21 to be 0, causing Line 44 to be blank, the Child's calculation (page 1) on Line 47 is correct. Do the same thing on the Parent's calculation (page 2) and Line 47 is wrong, as described in the original post.
Hopefully we'll see a fix from TT for this soon. Please? In the meantime, you can override Line 44, forcing it to be 0 (rather than blank) on the Parent's calculation, but I'd rather not have to do this for my final return.
