Claiming a dependent

My ex-wife claimed both of our children as dependents for 2019 because I was behind in child support payments at the end of the year.  I am now current and plan to claim one of the children per our divorce decree.  When I attempt to add my daughter as a dependent in TurboTax, it states that she does not qualify as a dependent.  I am assuming this is because of the situation from 2019 described above. 

 

First question is "how does TurboTax know this?". 

Second question is "how do I rectify this so that I can claim my daughter on my 2020 tax return?"