TurboTax is doing it correctly.
The earned income credit is first calculated (actually looked up
in a table) on your earned income; then it is calculated on your total income (AGI)*.
You get the lesser of the two calculated EIC numbers. See the 2018 EIC table
at:
https://taxmap.irs.gov/taxmap/instr/i1040gi-015.htm
*your earned income + your unemployment + any other income
