When the Iterative calculation does not end up being 'even', it uses the Alternative calculation, which often ends up as some missing credit and/or deduction.
I haven't checked in a few years so maybe they fixed it, but TurboTax also messes up the calculation if the Iterative calculation fluctuates between certain thresholds, especially the 400% threshold (but can also happen at the 200% and 300%).
Here are a couple of options that I can think of:
(1) Add a contribution to a Traditional IRA. That will usually save tax AND increase your credit, and may be enough to get it back to the Iterative calculation rather than the alternative calculation (or get it away from the x00% threshold).
(2) Manually calculate it. Then don't like the 1095-A to the business and enter manually calculated Self Employed Health Insurance deduction in the health insurance spot on the K-1 (as if it was not Marketplace insurance).
