So apparently the dual screen issue in Premiere Elements 10 demonstrated at Adobe Premiere Elements 10 Dual Screen Bugs - YouTube has not been addressed in Premiere Elements 14 five years later. (searches for this issue lead inevitably to that video).
I had to purchase PrE 14 for one of my users because our existing PrE 8 did not work on her Windows 10 laptop (Lenovo E560). The very first thing she did was open a Video Editor screen and move it to her external monitor (Samsung S27C450D) . Then she tried to maximize the window, and pop! it moved back to the laptop screen. When she moved it again and tried full screen, pop! back it went. When she move it again and just tried to resize it...you guessed it.
What's worse, if she moved the window to the second monitor, and tried to edit a video (leaving the window size alone), a "set in" caused the application and the entire system to freeze.
Does anyone know of a way to fix this?
She was able to edit her video if she left PrE on the laptop screen, so that's a temporary workaround.
I've asked her to try the dual screen tool in Expert Mode. But regardless of any tool built into the application, Windows users will expect to be able to use the multi-screen manipulation capabilities built into Windows. Please, Adobe, consider that in your UX design.
This is a user to user forum, not Adobe. You should contact Adobe at Adobe.com.
But that said, Adobe did address this and similar issues in version 14 and it seemed to fix it, at least in my experience.
But it may depend on which graphics card you have.
I'm sorry, but the issue does persist in PRE 14 because I've seen it happen. Without any more specific information, such as why the type of graphics card would make PRE fight with Windows for control, I can only conclude that your experience doesn't actually apply to the issue.