I'm experiencing issues with running Premiere Elements 14 on two displays.
I used to use expert mode in 'dual monitor workspace', moving the video window to the left monitor and keeping the timeline on the right monitor (both full screen). This worked fine for a couple of years.
Recently (possibly since upgrading to Sierra, but could be another issue) when I press play both windows jump to the left monitor. If I switch the position of the two windows then they both jump to the right monitor.
Running on a 2009 Mac Pro, 32gb Ram, two DELL P2714H displays, Sierra OS. Program is fully upgraded.