Code 1121 means that your tax return is being reviewed. The automated system has flagged something as being out of the ordinary, and your return is being queued for review by a human. This may or may not result in further investigation by the IRS.
TT has no control over which returns the IRS selects for this, but self-employment ones that show cash income or high deductions can be subject to extra scrutiny. You did not "pay extra so things like this wouldn't happen." TT is a computer program that you use to prepare your own tax returns.
