SE health insurance for greater than 2% shareholder of S Corp

[dhcpa]

I have a client that had health insurance on the MarketPlace in 2018.  Their total enrollment premiums were $24,611 & their APTC was $20,400.  Their MC wages were $20,000.  I have worked thru the worksheets in Pub 974.  Their modified AGI is $75,372 before any SE health ins. The federal poverty line is $16,240 putting them at 401%.  They paid $4,211 out of pocket and reported on their W-2. The end result on Form 8962 is that taxpayer has to pay all of the $20,400 back.

However,  I worked thru the calculation as if they had NOT received APTC and paid $20,000 of the premiums (since limited by MC wages) up front resulting in MAGI of $55,372.  The result is that they would qualify for $21,646 in PTC.  The taxpayer has sufficient shareholder distributions in 2018 to offset the entire MC wages of $20,000 as SE health insurance.  I am considering amending their W-2 to reflect the change.  I prepared the return with the assumption of $20,000 SE health insurance and the software is only calculating $2,966 as SE health insurance on Form 1040.  The calculated number flashes back and forth beween $20,000 and $2,966.  The end result is the taxpayer has to pay back $20,400 in APTC.  I understand this is a circular calculation.  What am I missing here?  Should the taxpayer have to pay $20,400 back when they would have qualified for a total PTC of $21,646 had they not taken the advance payment.  I realize I am posting this late but I hope you will have time to respond to my question.  Is ProSeries calculating SE health insurance correctly?

The shareholder has sufficient distributions to reclassify $20,000 as reim