@jloewenberg1 frankly, I would just file the return and worry about it later. It is highly, highly unlikely it is incorrect.
Also, since you are self employed, half the self-employment tax is also an :adjustment"". that could make up the remaining difference.
on the tax return, look at lines, 10 (normally just 1/2 of self-employment tax), line 12 (standard deduction) and line 13 (QBI) - is that the $21k.
