Issues with separate spaces rearranging windows for PhpStorm

I'm using PhpStorm with a detached Project window located on my second monitor. I have OSX setup to use different spaces for each monitor so I can have a menu bar on each monitor.

With this setting enabled, when I try to use the Project window that's located on a separate monitor, it automatically re-positions the Project window into the monitor/space that has the actual PhpStorm editor window.

I'm not sure if this is a PhpStorm bug or an OSX bug, but figured I'd ask if anyone's had this same issue before.