Calculations for HDHP 1 out of 12 months

We had an HDHP Plan in 1 out of 12 months.  When selecting none for the 11 months, each month selection increases the amount of tax.  However, in selecting the 11th month, there is a significant decrease in the amount of tax.  Is this an error?

 

Also, the questionnaire is asking about healthcare coverage in 2019.  Shouldn't this be asking about 2020?  This is the Home and Business 2020 version.