When converting, it is definitely not perfect. Given the resources I would review all of the 2018 returns for accuracy. That can help to prevent sucking up time during filing season. After a review, go to Screen 3 and look at the entry just BEFORE Organizer Miscellaneous. REMOVE the check box, then do the Proforma to 2019. This is especially important if you want state information to carry over correctly. Welcome to Lacerte! 

Possibly, if the 1040, Screen 7 - First entry is some number. It should be blank to not have any overpayment applied.