The software is subtracting self-employment tax deduction from my business income in order to determine my Qualified business income which in turn lowers my Qualified business income deduction. The 1040 instructions from the IRS do not say to subtract the self-employment tax deduction from business income when determining QBI.
Example results of turbo tax software:
Business income: $21,050
Self-employment tax deduction: -$1,329
QBI deduction: $3,944
From the 1040 instructions, page 34, "Determining Your Qualified
Business Income": "It also includes other
deductions attributable to the trade or
business including, but not limited to,
deductible tax on self-employment income"
