I am using two displays and since updating to High Sierra I'm experiencing weird behavior when opening files on the same space. I have a non-full-screen Finder window open on a Space on Display 2. When I open a file, such as a PDF, either by cmd-O or by double clicking, it will open in Preview on Display 1. This even happens when I have another Preview window open in the same Space on Display 2. And even when there's a full-screen app open on Display 1, then it'll move Display one to the first Space and open the PDF there. All apps are assigned to "None" under the Desktop options. How can I force macOS to open files on the same space or at least the same Display?
Update/additional information: The main issue seems to be with Preview. However, there is a similar thing happening with TextEdit. Opening a TextEdit document on Display 2 does open it right there. However, if I have a fullscreen app that is not TextEdit open on Display 1, then it switches Spaces left to either a space with a TextEdit document or a space with a Finder window.
Edit: Updating to Mojave did not change this behavior either.