FileMaker Pro 16 Advanced for Windows (All versions)
Have reproduced the issue on multiple systems and versions of Windows 10.
There are certain instances when the Script Workspace window will be pushed to the background of the main window. This happens while inline editing script steps, clicking the function button, and other activities. The issue does not occur 100% of the time, but can be reproduced with almost certainly using the method highlighted in the attached video.
In the video a new copy of the Contacts starter solution is opened. The Script Workspace is opened and a new script is created. A new If statement is created and the enter key is pressed. Then we mouse over to the fx icon. Once clicked, the Script Workspace window unexpectedly is moved to the background.
The Script Workspace window is brought back to the foreground and a new If statement is created. This time instead of hitting the enter key, we click on the white space. Again, the window is moved to the background.