I think it is your display settings, but I don't have total recall of which one. https://support.microsoft.com/en-us/windows/how-to-use-multiple-monitors-in-windows-329c6962-5a4d-b4... 

Can you drag other windows between monitors? If so, Lacerte should also work that way. I switched to an ultra wide monitor, so I can't test.  Contact Support , they should be able to help you.