Line 18 on the 2017 Iowa 1040 refers to the Health Insurance Deduction. As you saw, this should be any amounts for health insurance premium that are NOT already pretax (i.e., the amount with code DD, which is pretax because it is not included in your Wages in boxes 1, 3, and 5 on your W-2). So it seems that the State had the number correctly identified.
In my pre-existing test, line 18 was filled in with the self-employment health insurance deduction from a sole proprietorship and from Medicare premiums, both of which are correct. The code DD amount did not carry from the W-2.
Note that both my amounts carried over automatically from places on the federal return. In fact, I just walked through the Iowa interview (for 2018, because I don't have Iowa for 2017), and there wasn't even a place for me to manually enter an amount that would go to line 18.
So this suggests either a failure on the auto-import or a programming error (which is hard to believe because this would be such an obvious error).
In the process of reporting the problem that Critter described above, you will be asked to created a data file from your tax return. When you send this to the appropriate destination, the problem should be quite obvious to Support.
