I feel like mine just started doing this in the last month or so. I see you didn't get an answer and I have looked high and low to find a way to set a default monitor for forms. DId you find a way to do this other than changing your monitor identities in Windows? My software currently opens on monitor 3 and the forms pop out on 4. I think it may be set to follow the the software so that makes sense. I did have an issue with my monitors several months ago and may have accidentally changed the setting/identities.